少妇AV一区二区三区无|久久AV电影一区三|日本一级片黄色毛片|亚洲久久成人av在线久操|黄色视频在线免费看呀一区二区|综合精品视频精品久久久浪朝|亚洲午夜成人资源|欧美黄色一级片黑寡妇|内射无毛少妇特写|无码农村夜晚偷拍啪啪

2011職稱英語理工類完型填空預(yù)測題及答案(1)

時間:2010-09-21 11:31:00   來源:無憂考網(wǎng)     [字體: ]
2011職稱英語理工類完型填空預(yù)測題及答案(1)

 閱讀下面的短文,文中有15處空白,每處空白給出了4個選項(xiàng),請根據(jù)短文的內(nèi)容從4個選項(xiàng)中選擇1個答案。

Earth's Inner Core

  Scientists have long struggled to understand what lies at the planet's center. Direct observation of its center is impossible, so researchers must (1) to other evidence.

  In 1889, a German scientist detected a severe earthquake in Japan. Geophysicists concluded that shock waves (2) jolts (晃動) from one side of Earth through the center to the other side. Then in 1936, Danish geophysicist Inge Lehmann studied the waves' (3) to determine that within Earth's core of molten (熔化了的) iron lies a solid inner core - but (4) that core was made of eluded (難倒) her. Other geophysicists quickly determined that Lehmann's inner core was composed mostly (5) iron. Since then, Lehmann's discovery has (6) conventional Earth science.

  But now scientists are challenging traditional theory with new and radical (7). For example, Earth's center could actually contain an "inner core within the inner core," claim Ishii and colleague Adam Dziewonski.

  Analyzing hundreds of thousands of earthquake wave (8), they maintain that the inner core has at its heart a tiny, even more solid sphere (球體). This sphere "may be the oldest fossil (9) from the formation of Earth," says Dziewonski.

  Dziewonski and Ishii speculate that shortly (10) Earth formed around 4.8 billion years ago, a giant asteroid (小行星) smashed into the young planet and nearly melted it. But Earth's center didn't quite melt; it (11) mass as the planet cooled. The core within a core may be the kernel (核心) that endured. "Its presence could change our basic ideas about the (12) of the planet," Dziewonski says.

  Dziewonski's idea is tame (溫和的) compared to the (13) theories of independent geophysicist J. Marvin Herndon. Earth's inner core is made not of iron, he claims, but a (14) of nickel and silicon. Herndon has a truly revolutionary notion: Within the nickel silicide (硅化物) inner core is also an "inner" inner core - an 8 km-wide ball of the element uranium. Uranium is radioactive. Herndon thinks the uranium releases heat energy as its atoms (15) fission-split and crash into one another in a chain reaction. In other words, we may live on top of a gigantic, "natural" nuclear power plant.



  1 A try B leave C turn D point

  2 A create B receive C feel D overcome

  3 A work B solution C job D patterns

  4 A whether B what C why D how

  5 A from B within C of D to

  6 A followed B dominated C restored D opposed

  7 A ideas B demands C phenomena D movements

  8 A things B acts C methods D records

  9 A taken B benefited C left D kept

  10 A after B before C since D when

  11 A expanded B modified C gained D melted

  12 A size B origin C structure D shape

  13 A radical B traditional C classical D conventional

  14 A system B copy C model D compound

  15 A charge B last C experience D show

  【參考答案】

  1. C 2. A 3. D 4. B 5. C

  6. B 7. A 8. D 9. C 10. A

  11. C 12. B 13. A 14. D 15. C