2013年职称英语等级考试(理工类A级)真题(4)

Right B.Wrong C.Not mentioned

5小题>、 The MIT team had tried different materials befoie they studied natural silk in their research. A. Right B.Wrong C.Not mentioned

6小题>、 Carbon nanotubes are currently the most popular topic in materials science.

A. Right B.Wrong C.Not mentioned

7小题>、 It is indicated that materials strongcr than natural silk can be expected in the future. A. Right B.Wrong C.Not mentioned

三、概括大意与完成句子

第17题： Black Holes 1. Black holes can be best described as a sort of

vacuum,sucking up everything in space. Scientists have discovered that black holes comle from an cxplosion of huge stars. Stars that are near death can no longer burn due to loss of fuel,and because its temperature can no longer control the

gravitational(重 力的)force,hydrogen ends up putting pressure onto the star's

surface until it suddenly explodes then collapses. 2. Black holes come from stars that are made of hydrogen,other gases and a few metals. When thesc explode it can turn into a stellar-mass（恒星质量）black hole,which can only occur if the star is largc enough(should be bigger than the sun) for the explosion to break it into

pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that's only a fraction of an inch! 3. Objects that get sucked in a black hole will always remain there,never to break free. But re- membcr that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place. Orbits （轨道）do not changc because the newly formed black hole contains exactly the same amount of mass as when it was a star,only this time its mass is totally contractcd that it can end up as no bigger than a state. 4. So

far,astronomcrs have figured OLit that black holes exist because of Albert

Einstein's theory of relativity. In the end,through numerous studies,thcy have discovered that black holes truly exist. Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a tclcscope. 13ut astronomers continue to study galaxies（银河系）,space and the solar system to under- stand hc)w black holes might evolve. It is possible that black hole.s can exist for millions of years,and later contribute to a bigger process in

galaxies,which can eventually lead to creation of new entities. Scicntists also

credit black holes as helpful in learning how galaxies began to form. 下面的短文后有2项测试任务：(1)第23~26题要求从所给的6个选项中为第1~4段每段选择1个最佳标题；(2)第27~30题要求从所给的6个选项中为每个句子确定1个最佳选项。 A.Is there proof that black holes really exist? B. What are different types of black holes? C. How are black holes formed? D. How were black holes named? E. What happens to the objects around a black hole? F. What are black holes made of?

1小题>、 23. Paragrahp1

2小题>、 24. Paragrahp2