为帮助广大考有效备考2012年职称英语考试，中国职称英语考试网站编辑特为您整理了职称英语理工类完型填空模拟练习题，希望对您的考试有所帮助！
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 （晃动） 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 （难倒） 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 （球体）. 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 （温和的） 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
参考答案:
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
特别提醒：为了方便广大考生（或学员）及时查询成绩，中大网校还为您提供了考试成绩查询信息免费短信提醒服务，我们会将考试成绩查询相关信息第一时间发送到您的手机上。点击订阅免费短信提醒服务!
考前培训：为帮助广大学员有效备战2012年职称英语考试，中国职称英语考试网站现特别打造了考前辅导八折优惠套餐，本班次可以帮助广大学员全程强化教材基础知识，系统掌握考试答题方法与技巧，并在短时间内抓住考试考点，现在报名原价500元/科，现价400元/科，八折优惠！机会难得，还等什么，快来参加2012年职称英语考试前辅导吧，点击报名>>>
编辑推荐：
