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Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials

What does the author imply about the raw materials used to make glass?

A. They are transparent

B. They were the same for centuries

C. They are very heavy

D. They are liquid

1
10 tháng 8 2019

Đáp án B
Nói về các nguyên liệu làm nên thủy tinh, đáp án của câu hỏi nằm ở dòng thứ 2 và 3 của đoạn số 2. Câu nói
đã nêu rõ nguồn gốc ban đầu thủy tinh được làm qua từ “made from a mixture of (được làm từ hỗn hợp)” và
“remained the basic ingredients of glass … in the seventeenth century (duy trì những nguyên liệu cơ bản của thủy
tinh..cho tới tận thế kỉ thứ 17)

Read the following passage and then choose the best answer A, B, C or D.          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in...
Đọc tiếp

Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

According to the passage, why can glass be more easily shaped into specific forms than can metals?

A. It has better optical properties

B. It retains heat while its viscosity changesv

C. It gradually becomes softer as its temperature rises

D. It resists breaking when heated

1
14 tháng 5 2017

Đáp án C
Nhìn vào dòng số 2 và 3 của đoạn cuối cùng ta có thể thấy rõ được đáp án: “Unlike metals that flow or
“freeze” at specific temperatures, glass progressively softens as the temperature rises (thủy tinh mềm dần khi
nhiệt độ tăng)

Read the following passage and then choose the best answer A, B, C or D.          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in...
Đọc tiếp

Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials

According the passage, how is glass that has cooled and become rigid different from most other rigid substances?

A. It has varying physical properties

B. It has an interlocking crystal network

C. It has unusually low melting temperature

D. It has a random molecular structure

1
21 tháng 12 2018

Đáp án D
Dòng thứ 6 của đoạn 2 đã chỉ ra rất rõ đáp án cho câu hỏi này: “but in contrast to most materials formed in
this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead
retains the random molecular structure of a liquid (còn giữ lại một kết cấu phân tử ngẫu nhiên của thể lỏng.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms - as table ware, containers, in architecture and design - glass represents a major achievement in the history of technological developments.

Since the Bronze Age about 3,000 B.C., glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed by melting then cools to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow. Why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or "freeze" at specific temperatures glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the shape achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

What does the author imply about the raw materials used to make glass?

A. They were the same for centuries

B. They are liquid.   

C. They are transparent

D. They are very heavy

1
6 tháng 2 2018

Đáp án A.

Key words: raw materials, make glass.

Clue: “It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century.” Thủy tinh được làm từ hỗ hợp silic, thép, chất kiềm ví dụ như Natri cacbonat hoặc Kali cacbonat, và đây vẫn là các nguyên liệu cơ bản của thủy tinh cho đến khi có sự phát triển của thủy tinh chì vào thế kỷ 17.

Phân tích: Đến thế kỷ 17, các nguyên liệu cơ bản để tạo ra thủy tinh vẫn không thay đổi. Do đó, chọn đáp án    A. They were the same for centuries: Các nguyên liệu thô vẫn như vậy trong nhiều thế kỷ.

Các đáp án khác không phù hợp:

B. They are liquid: Các nguyên thô là chất lỏng.

C. They are transparent: Các nguyên liệu thô trong suốt.

D. They are very heavy: Các nguyên thô rất nặng.

Read the following passage and then choose the best answer A, B, C or D.          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in...
Đọc tiếp

Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials

The word “durable” in paragraph 1 is closest in meaning to

A. delicate

B. plain

C. lasting

D. heavy

1
3 tháng 7 2018

Đáp án C
Durable = lasting: lâu bền

Read the following passage and then choose the best answer A, B, C or D.          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in...
Đọc tiếp

Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials

The word “customarily” in paragraph 2 could be best replaced by”……………”

A. certainly

B. naturally

C. usually

D. necessarily

1
11 tháng 9 2019

Đáp án C
Customarily = usually: theo lẽ thường, thông thường

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.   Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

  Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms - as table ware, containers, in architecture and design – glass represents a major achievement in the history of technological developments.

  Since the Bronze Age about 3,000 B.C., glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed by melting then cools to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow. Why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

  Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the shape achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

The word “durable” in paragraph 1 is closest in meaning to ______ .

A. lasting

B. delicate

C. heavy

D. plain

1
15 tháng 2 2019

Đáp án A.

Dịch nghĩa: Từ “durable” trong đoạn 1 gần nghĩa nhất với _________.
A. lâu dài
B. mỏng manh
C. nặng
D. nhạt nhẽo

Dịch bài

  Thủy tinh là một chất đáng chú ý được làm từ các nguyên liệu thô đơn giản nhất. Nó có thể có màu hoặc không màu, đơn sắc hoặc đa sắc, trong suốt, trong mờ hoặc mờ đục. Nó nhẹ và không thấm vào chất lỏng, dễ dàng làm sạch và tái sử dụng, bền nhưng dễ vỡ và thường rất đẹp. Kính có thể được trang trí theo nhiều cách và tính chất quang học của nó là đặc biệt. Trong tất cả vô số các dạng của nó - như đồ dùng để bàn, hộp đựng, trong kiến ​​trúc và thiết kế - thủy tinh đại diện cho một thành tựu lớn trong lịch sử phát triển công nghệ.

  Kể từ thời đại đồ đồng khoảng 3.000 trước công nguyên, thủy tinh đã được sử dụng để chế tạo các loại đồ vật khác nhau. Nó lần đầu tiên được làm từ hỗn hợp silica, dòng và chất kiềm như soda hoặc kali, và đây vẫn là những thành phần cơ bản của thủy tinh cho đến khi phát triển thủy tinh chì trong thế kỷ XVII. Khi được đun nóng, hỗn hợp trở nên mềm và dễ uốn và có thể được tạo bằng các kỹ thuật khác nhau thành một loạt các hình dạng và kích cỡ. Do đó, khối đồng nhất được hình thành bằng cách nấu chảy sau đó để nguội để tạo ra thủy tinh, nhưng ngược lại với hầu hết các vật liệu được hình thành theo cách này (ví dụ kim loại), thủy tinh thiếu cấu trúc tinh thể mà thường liên kết với chất rắn, và thay vào đó giữ lại cấu trúc phân tử ngẫu nhiên của chất lỏng. Trong thực tế, khi thủy tinh nóng chảy nguội đi, nó dần dần cứng lại cho đến khi cứng, nhưng làm như vậy mà không thiết lập một mạng lưới các tinh thể lồng vào nhau mà thường được liên kết với quá trình đó. Đây là lý do tại sao kính vỡ dễ dàng khi xử lý một cú đánh. Tại sao thủy tinh xuống cấp theo thời gian, đặc biệt là khi tiếp xúc với độ ẩm và tại sao dụng cụ thủy tinh phải được hâm nóng từ từ và làm nguội đồng đều sau khi sản xuất để giải phóng các ứng suất bên trong do làm mát không đều.

  Một đặc điểm khác thường của thủy tinh là cách thức thay đổi độ nhớt của nó khi nó chuyển từ chất lạnh thành chất lỏng nóng dễ uốn. Không giống như các kim loại chảy hoặc đóng băng ở nhiệt độ cụ thể, thủy tinh sẽ mềm dần khi nhiệt độ tăng, trải qua các giai đoạn khác nhau của tính dễ uốn cho đến khi nó chảy như một xi-rô dày. Mỗi giai đoạn của tính linh hoạt cho phép thuỷ tinh được chế tác thành nhiều dạng khác nhau, bằng các kỹ thuật khác nhau và nếu làm mát đột ngột, vật thể vẫn giữ được hình dạng đạt được tại thời điểm đó. Do đó, thủy tinh có thể tuân theo số lượng kỹ thuật tạo nhiệt lớn hơn hầu hết các vật liệu khác.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.         Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical...
Đọc tiếp

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

        Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms - as table ware, containers, in architecture and design - glass represents a major achievement in the history of technological developments.

        Since the Bronze Age about 3,000 B.C., glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed by melting then cools to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow. Why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

        Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the shape achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

The word “durable” in paragraph 1 is closest in meaning to _________.

A. lasting

B. delicate

C. heavy

D. plain

1
24 tháng 1 2017

Chọn A

Read the following passage and then choose the best answer A, B, C or D.          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in...
Đọc tiếp

Read the following passage and then choose the best answer A, B, C or D.

          Glass is a remarkable substance made from simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful. Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms-as table ware, containers, in architecture and design-glass represents a major achievement in the history of technological developments.

          Since the Bronze Age about 3,000 B.C, glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft, and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass is thus formed by melting then cooling to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow, why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures, glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the stage achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

What must be done to release the internal stresses that build up in glass products during manufacture?

A. The glass must be cooled quickly

B. The glass must be reheated and evenly cooled

C. The glass must be kept moist until cooled

D. The glass must be shaped to its desired form immediately

1
22 tháng 12 2018

Đáp án B
Đáp án nằm ở câu cuối cùng của đoạn số 2: “and why glassware must be slowly reheated and uniformly
cooled after manufacture to release internal stresses (để giải phóng áp lực bên trong) induced by uneven cooling.”

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.   Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 38 to 42.

  Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms - as table ware, containers, in architecture and design – glass represents a major achievement in the history of technological developments.

  Since the Bronze Age about 3,000 B.C., glass has been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated, the mixture becomes soft and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed by melting then cools to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow. Why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses induced by uneven cooling.

  Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or “freeze” at specific temperatures glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the shape achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.

The word “customarily” in paragraph 2 could best be replaced by “__________”.

A. naturally

B. necessarily

C. usually

D. certainly

1
8 tháng 4 2018

Đáp án C.

Dịch nghĩa: Từ “customarily” trong đoạn 2 có thể được thay thế tốt nhất bởi __________.
A. tự nhiên
B. cần thiết
C. thường xuyên
D. đương nhiên