共用题干 Eastern Quakes can Trigger Big ShakesIn the first week of November 2011...

作者: tihaiku 人气: - 评论: 0

问题共用题干 Eastern Quakes can Trigger Big Shakes

In the first week of November 2011,people in central Oklahoma experienced more than two dozen earth-
quakes.The largest,a magnitude（量）5.6 quake,shook thousands of fans in a college football stadium,
caused cracks in a few buildings and scared many people who had never felt a quake before.Oklahoma is not
an area of the country famous for its quakes.If you watch the news on TV,you will see reports about all sorts
of natural disasters.But the most dangerous type of natural disaster,and also the most unpredictable,is the
earthquake.
Researchers at the US Geological Survey(USGS)estimate that several million earthquakes occur globally
each year. That may sound scary,but people don't feel many of them because they happen in remote and
unpopulated regions.Many quakes happen under the ocean,and others have a very small magnitude.
Scientists know about small,remote quakes only because of very sensitive electronic devices called seis-
mometers（地震仪）.These devices detect and measure the size of ground vibrations（震颤）produced by
earthquakes.Altogether,USGS researchers use seismometers to identify and locate about 20,000 earthquakes
each year.
Although earthquakes can happen anywhere in the world,really big quakes occur only in certain areas.
The largest ones register a magnitude 8 or higher and happen,on average,only once each year. Such big
ones typically occur along the edges of Earth ' s tectonic plates（构造板块）.
Tectonic plates are huge pieces of Earth ' s crust（外壳）,sometimes many kilometers thick. Often,
edges of these plates temporarily lock together. When plates push and scrape（擦）past each other earthquakes
occur. On average,tectonic plates move very slowly一about the same speed as your fingernails grow.
But sometimes earthquakes rumble（轰轰作响）through portions of the landscape far from a plate ' s
edges.Although less expected,these"mid-plate"small earthquakes can do substantial damage.Some of the
biggest known examples hit the eastern half of the United States two centuries ago.Today,scientists are still
puzzling over why the quakes occurred and when similar ones might occur.

选项 The earthquake that hit the eastern half of the United States two centuries ago is the biggest"mid-plate" one in history. A:Right B:Wrong C:Not mentioned

答案 B

解析由文章第一段第三句话“Oklahoma is not an area of the country famous for its quakes.”可知，俄克拉荷马州不是美国以地震多发而扬名的州，故应选B。
由文章第一段最后一句话“But the most dangerous type of natural disaster, and also themost unpredictable, is the earthquake”可知，应选A。
由文章第二段第二句中“people don' t feel many of them because they happen in remoteand unpopulated regions”可知，在发生的多次地震中，只有很少的会被人们感觉到，因为多数的地震都发生在遥远的无人区，故选B。
文章第三段中仅仅提到了地震仪能够监测到地震导致的地面震颤的面积和科学家们用这种仪器所监测到的地震数目，故选C。
由文章第四段最后两句的内容可知，8级或更高的大地震多发于地壳构造板块的边缘，故选A。
由文章第五段第三句“When plates push and scrape past each other earthquakes occur.”以及常识可知，地壳板块只有在相互推挤和摩擦时地震才会发生，并不是任何一次的板块移动都会导致地震，故选B。
文章最后一段中提到，两个世纪前几次最强的板块中部地震袭击了美国东半部地区，但文中只说这些是已知的地震中最强的几次，并未表明这几次地震中的某一次地震是历史上最强的，故选B。第3部分：概括大意与完成句子

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共用题干 Eastern Quakes can Trigger Big ShakesIn the first week of November 2011...

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