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
Giải bởi qa.haylamdo.com
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)
The teachers are, at the moment, trying their best ______ all the necessary that their students may need for their critical examination while, sadly, some do not seem to appreciate that
UNESCO stands _______ United Nations Educational, Scientific and Cultural Organization
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) that is CLOSEST in meaning to the underlined part in each of the following questions.
We, the young, should take actions to raise people’s awareness of being concerned with sewage processing measures from now on
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) that is CLOSEST in meaning to the underlined part in each of the following questions.
Who will replace you to monitor the class on the days you are on duty next week?
Read the passage bellow and then choose a suitable word A, B, C or D to fill in each blank.
The Earth's Energy Budget
The way the Earth interacts ___ (35)___ the sun's energy can be displayed in a diagram called the Earth’s energy budget. It displays the sun's energy that reaches us and how much of that energy absorbed and reflected is by the earth and___(36)___ atmosphere. Solar energy reaches earth as electromagnetic radiation. Once the energy reaches earth, some of it is absorbed by the atmosphere, ___(37)___ clouds.
Some of it makes it to the earth's surface, and is ___(38)___ by land and oceans. The ___(39)___ of energy absorbed affects temperature. The energy ___(40)___ is not absorbed by the earth or its atmosphere is reflected. back out to space in the same wavelengths in which it came to earth. On ___(41)___, the amount of energy coming in is equal to the amount of energy going out. Therefore, we say the earth's energy budget is balanced. ___(42)___ more energy was coming in than was going out, the earth's temperature would increase. On the other hand, if too much energy is reflected, and not absorbed, we'll see a ___(43)___ in the earth's temperatures. Of all of the sun's energy that hits the Earth, about 70% is absorbed by ___(44)___ land, ocean, atmosphere and clouds and about 30% is reflected back into space.Question 42
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) that is OPPOSITE in meaning to the underlined part in each of the following questions
Most of the female football players will be jobless when the Games are over
Choose one of the given options which is incorrect
In this organization, all members are equal. No members will use force against together
Choose one of the given options which is incorrect
Working for this organization will give a chance to help improve international healthy care
Peter said to Jane carrying a heavy suitcase: “Need a hand with your suitcase, Jane?”
Jane: “_______.”
Mark the letter A, B, C or D on your answer sheet to indicate the word(s) that is OPPOSITE in meaning to the underlined part in each of the following questions
Under ideal conditions, the entire life cycle of some insects, for example fleas, living on pets, may only take 3 weeks, so in no time at all, pets and homes can be infested
So nervous about the exam ______ he sat in silence although the surrounding students were talking loudly
You should ______ think about what technical school to apply for; or else, you will waste your time and money in a few years later
