考研考博-考博英语-中国科学院模拟考试题含答案23.docx

考研考博-考博英语-中国科学院模拟考试题含答案1. 单选题The old belief that the universe never changes is quite wrong. Even before the invention of the telescope, astronomers noticed that bright stars suddenly appear in the sky，and then later disappear. （1）In fact we now know that they are really old stars which are slowly dying. A recent case of a nova occurred in 1918，and one of the few people who saw this was the American astronomer Edward Barnard. He was driving along in a car, occasionally looking up into the sky. Suddenly he noticed a star that he had never seen before, and exclaimed, “That star should not be there!” He was in fact watching the explosion of a nova.（2）As they do so, they let out huge clouds of material. Sometimes as large as the earth, and these explode into space at a speed of about 8，000, 000 kilometers per hour. When this happens, the hotter parts of the star become visible, and this is why novae are so bright. Although the explosions are huge on a human scale, they only consume a small part of the dying star’s energy. （3）Indeed, there are even some stars which explode once a fortnight.There are other old stars which do not die slowly, but are completely destroyed by one great explosion. （4）The explosion of a supernova is equivalent to about a million, million, million, million hydrogen bombs going off at the same time. Just before the explosion the star’s density become very great and it spins at a very high speed. A matchbox of material taken from the star at that time would weigh about 1,000 tons, and the star would be turning at about 16,000, 000 kilometers per hour.（5）One supernova which Chinese astronomers observed in 1054 can still be seen by us today. It has been shining for at least nine hundred years.问题1选项A.Novae are old stars which are slowly dying.B.They are known as “supernovae.”C.The death is a slow one, and the star may continue to explode for thousands of years.D.The explosion of a supernova is like a cosmic bomb.E.The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.F.These stars were called “novae” because they were thought to be new.问题2选项A.Novae are old stars which are slowly dying.B.They are known as “supernovae.”C.The death is a slow one, and the star may continue to explode for thousands of years.D.The explosion of a supernova is like a cosmic bomb.E.The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.F.These stars were called “novae” because they were thought to be new.问题3选项A.Novae are old stars which are slowly dying.B.They are known as “supernovae.”C.The death is a slow one, and the star may continue to explode for thousands of years.D.The explosion of a supernova is like a cosmic bomb.E.The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.F.These stars were called “novae” because they were thought to be new.问题4选项A.Novae are old stars which are slowly dying.B.They are known as “supernovae.”C.The death is a slow one, and the star may continue to explode for thousands of years.D.The explosion of a supernova is like a cosmic bomb.E.The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.F.These stars were called “novae” because they were thought to be new.问题5选项A.Novae are old stars which are slowly dying.B.They are known as “supernovae.”C.The death is a slow one, and the star may continue to explode for thousands of years.D.The explosion of a supernova is like a cosmic bomb.E.The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.F.These stars were called “novae” because they were thought to be new.【答案】第1题:A第2题:A第3题:C第4题:B第5题:E【解析】（1）空格处后面一句话有两个关键点，一是in fact,”实际上”的意思，表示与前文（空格处所填入的句子）是转折关系；另一个关键点是old的这个词，既然前后是转折关系，那么空格处会有一个与old相反的表述。

综上，These stars were called “novae” because they were thought to be new.符合题意2）空格处位于句首，因此可以考虑是一个主题句，即后面的内容都是围绕这个句子展开因此需要把握整段文字的主要内容：讲述了一颗新星慢慢衰落的过程，因此Novae are old stars which are slowly dying符合题意3）空格处前面讲述了恒星爆炸，空格处后一句讲述的是”甚至有些恒星会每两周爆炸一次”，言下之意是有些恒星的爆炸并不是只有一次，可能会延续很长时间，因此The death is a slow one, and the star may continue to explode for thousands of years.符合题意4）空格后的句子提到了一个关键词supernova，因此，空格处需要将这个概念引出来再联系空格前一句中的other old stars可知They are known as “supernovae.”符合题意5）空格后的句子提到”中国天文学家在1054年观测到的一颗超新星至今仍可看见”，这个例子说明超新星爆炸后仍然可以长时间发光，因此The explosion itself occurs suddenly, in the space of a minute, but the supernova continues to shine long after the event.符合题意。

2. 单选题We’ve all heard about endangered animals. Creatures like the critically endangered black rhinoceros are famous. But what are the most endangered plants? They might not 。