题目内容
A．qualityB．colourC．weightD．location
查看答案
搜索结果不匹配？点我反馈
更多问题
Which of the following is NOT true of the British football players？
根据下列文章,请回答 23～30 题。
Early Ideas about the Universe
1 Early man got his ideas about the universe by looking at the stars as you do. He observed carefully, and learned many things about the sun, the moon, and the stars.
2 Suppose you were asked to collect evidence about the sun as early man did. You might go out morning after morning and see it come up in the east. Even on cloudy mornings, you would observe that the darkness goes away and the world becomes light. You might not see the sun but would be sure it is there, because you notice that the earth warms up. As you continued, the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.
3 After a while the sun stays in the sky for shorter and shorter periods. Many plants begin to die. Leaves fall. Winter comes. Year after year this is repeated and you cannot tell exactly why it happens. But you realize that the sun seems to make the difference. Primitive (原始的) man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship (崇拜) a sun-god, but primitive man was right about the importance of the sun to life on earth.
4 You have been told that the world is round. But suppose no one had ever taught you that the world was like a huge ball. Would you have ever thought of it yourself？ You cannot see the curve (曲线) of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat. Such ideas appeared from the evidence they had.
5 If you watch the stars night after night, you will see them rise and set. As you look at the sky, it is not difficult to imagine that you are in the center of a vast collection of twinkling (闪烁) lights. Some early astronomers (天文学家) believed the sky was a crystal shell or series of crystal shells, one inside the other. They believed this because that is what the night sky looked like. For many centuries, men believed that the earth was the center of the universe and that the sun, the moon, and the stars circled around it.
第 23 题 Paragraph 2________
根据下列文章,请回答 31～35 题。
Black Holes
What is a black hole？ Well, it's difficult to answer this question, since the terms we normally use to describe a scientific phenomenon are inadequate here. Astronomers and scientists think that a black hole is a region of space (not a thing) into which matter has fallen and from which nothing can escape -- not even light. So we can't see a black hole. A black hole exerts (施加) a strong gravitational (重力的) pull and yet it has no matter. It is only space -- or so we think. How can this happen？
The theory is that some stars explode ,when their density increases to a particular point; they "collapse" and sometimes a supernova (超新星) occurs. The collapse of a star may produce a "White Dwarf (白矮星) " or a "neutron star"-- a star whose matter is so dense that it continually shrinks by the force of its own gravity. But if the star is very large this process of shrinking may be so intense that a black hole results. Imagine the earth reduced to the size of a marble, but still having the same mass and a stronger gravitational pull, and you have some idea of the force of a black hole. Any matter near the black hole is sucked in. It is impossible to say what happens inside a black hole.
Our space and time laws don't seem to apply to objects in the area of a black hole. Einstein's relativity theory is the only one that can explain such phenomena. Einstein claimed that matter and energy are interchangeable, so that there is no "absolute" time and space. There are no constants at all, and measurements of time and space depend on the position of the observer -- they are relative. Einstein's theory provided a basis for the idea of black holes before astronomers started to find some evidence for their existence. It is only recently that astronomers have begun specific research into black holes.
The most convincing evidence of black holes comes from research into binary (由两部分组成的) star systems. In some binary star systems, astronomers have shown that there is an invisible companion star, a "partner" to the one which we can see in the sky. There is one star, called by its catalogue number HDE 226868, which must have a partner. This partner star, it seems, has a mass ten or twenty times greater than the sun-- yet we can't see it. Matter from HDE 226868 is being dragged towards this companion star. Could this invisible star, which exerts such a great force, be a black hole？ Astronomers have evidence of a few other stars too, which might have black holes as companions.
第 31 题 Which of the following does NOT fit the definition of the black hole？
China's Three Gorges Dam is
微信支付 
支付宝支付