试题与答案

关于电话的几种叙述中正确的是( ) A.话筒的作用是把声音直接传到对方的听筒 B

题型:选择题

题目:

关于电话的几种叙述中正确的是(  )

A.话筒的作用是把声音直接传到对方的听筒

B.话筒的作用是把电流变为声音

C.当听筒的螺线管里的电流大小变化时,听筒内振动膜(薄铁片)振动起来发出声

D.听筒和话筒里都有碳粒,其作用是保护振动膜

答案:

电话由话筒和听筒组成.话筒里有碳粒是为利用碳粒电阻大小随松紧而变化使电路中产生随声音大小的电流;听筒中没有碳粒,只有螺线管、永磁铁和薄铁片,电路中有随声音大小而变化的电流时,螺线管磁性强弱随之变化,使薄铁片受到的吸力大小发生变化从而振动起来而发声.

故选C.

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(2)这首诗表达了作者怎样的复杂情感?(4分)\

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题型:阅读理解

Stephen William Hawking was born on January 8th, 1942 in Oxford, England. His parents’ house was in North London, but during the Second World War Oxford was considered a safer place to have babies. When he was eight, his family moved to St Albans. At eleven Stephen went to St. Albans School, and then on to University College, Oxford, his father’s old college. Stephen wanted to do math, although his father would have preferred medicine. Math was not available at University College, so he did physics instead. 

Stephen then went on to Cambridge to do research in Cosmology (宇宙论). After gaining his Ph.D. (哲学博士)he became first a Research Fellow, and later on a Professorial Fellow at Gonville and Caius College. After leaving the Institute of Astronomy in 1973, Stephen came to the Department of Applied Math and Theoretical Physics (理论物理), and since 1979 has held the post of Lucasian Professor of math.

Stephen Hawking has worked on the basic laws which rule the universe. With Roger Penrose he showed that Einstein’s General Theory of Relativity implied space and time would have a beginning in the Big Bang and an end in black holes. These results show it was necessary to unify(统一)General Relativity with Quantum Theory (量子论). One result of such a unification that he discovered was that black holes should not be completely black, but should give off radiation and disappear in the end.

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A. He once studied at the same college that his father studied at.

B. At one time he did research in Cosmology in Oxford. 

C. He preferred math to medicine at college.

D. He contributed to the unification of General Theory of Relativity and Quantum Theory.

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A. able to be had              B. allowed to study   

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A. Because they liked it better than North London.

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B. Big Bang, a great theory 

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D. The unification of two theories

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