职称英语考试理工类真题精选—完型填空
阅读下面的短文,文中有15处空白,每处空白给出了4个选项,请根据短文的内容从4个选项中选择1个最佳答案,涂在答题卡相应的位置上。
Earth#39;s Inner Core
Scientists have long struggled to understand what lies at the planet#39;s center, Direct observation of its center is impossible,so researchers must_____(51)to other evidence.
In 1889,a German scientist detected a severe earthquake in Japan.Geophysicists concluded that shock waves_____(52)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______(53) to determine that within Earth#39;s core of molten(熔化了的)iron lies a solid inner core-but_____ (54)that core was made of eluded(难倒)her.Other geophysicists quickly determined that Lehmann#39;s inner core was composed mostly_____(55)iron. Since then,Lehmann#39;s discovery has_____(56)conventional Earth science.
But now scientists are challenging traditional theory with new and radical _____(57) For example,Earth#39;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 _____(58),they maintain that the inner core has at its heart a tiny, even more solid sphere(球体) . This sphere#39;#39;may be the oldest fossil____(59)from the formation of Earth,”says Dziewonski.Dziewonski and Ishii speculate that shortly_____(60) Earth formed around 4.8billion years ago,a giant asteroid(小行星)smashed into the young planet and nearly melted it. But Earth#39;s center didn#39;t quite melt;it______(61)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_____ (62)of the planet,”Dziewonski says idea is tame(温和的)compared to the_____(63)theories of independent geophysicist J.Marvin Herndon.Earth#39;s inner core is made not of iron,he claims but a_____(64)of nickel and si icon Hemdon 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.Hemdon thinks the uranium releases heat energy as its atoms_____(65)fission-split and crash into another in a chain reaction. In other words,we may live on top of a gigantic, “natural”nuclear power plant.
51 A try
B leave
C turn
D point
52 A create
B receive
C feel
D overcome
53 A work
B solution
C job
D patterns
54 A whether
B what
C why
D how
55 A from
B within
C of
D to
56 A followed
B dominated
C restored
D opposed
57 A ideas
B demands
C phenomena
D movements
58 A things
B acts
C methods
D records
59 A taken
B benefited
C left
D kept
60 A after
B before
C since
D when
61 A expanded
B modified
C gained
D melted
62 A size
B origin
C structure
D shape
63 A radical
B traditional
C classical
D conventional
64 A system
B copy
C model
D compound
65 A charge
B last
C experience
D show
参考答案
51 c turn to other evidence:寻求其他证据。Tum to属固定搭配。
52 A create jolts:造成震动。其他几个选项意思不符。
53 D wayes#39;patterns:波浪的形状。科学家通过研究震波的形状了解地球的情况。
54 B 此处的意思是地心是由什么构成的难倒了她。这里应使用what构成名词性从旬,作主语。
55 c compose of:由……组成。固定短语。
56 B dominate:占统治地位,支配。Lehamann的发现在传统地球科学领域占统治地位。
57 A 此处的意思是:现在的科学家正用新的、激进的观点挑战传统的理论。本题只有填ideas才符合本句的意思。
58 D 此处填records,本句的.意思是:通过分析数十万次地震波的记录,他们认为……。其他几个选项与句意不符。
59 c left:留下来的。此处的意思是:这一球体可能是地球形成时留下来的最古老的化石。
60 A 依据上下文,应用afte~句子意思才讲得通。
61 c gain:获取。gained mass as the planet cooled:在星球(这里指地球)变冷的过程中,它逐渐获得了质量。
62 B 本文主要谈地球起源问题,故此处应填ongm.
63 A 本句前面出现的一个词是“tame”,与之对应,应该是“radical”。
64 D nickel和silicon的混合物,compound:混合物。
65 c fission—split:裂变。经历裂变,用动词experience.
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