Question

    On the morning of July 4, a magnitude 6.4 earthquake rocked Southern California, destroying roads and sending people fleeing to safety. But that wasn't all the Earth had in store: Less than a day and a half later, a powerful magnitude7. I earthquake shook again. While earthquakes are not unexpected, the two most recent earthquakes are the largest that have struck this area in at least two decades. And a series of large and small aftershocks are expected on the way.

The two earthquakes struck in what's known as the Eastern California shear zone, where the Pacific Plate crushed against the North American Plate. The recent events occurred when two blocks of Earth moved side by side.

They seemed to have occurred along the same set of faults (断层)lying in an area known as the Little Lake fault zone-in most circumstances, earthquakes hit in a familiar order: There's a large earthquake followed by a series of smaller events. That's because the movement that occurs during a large earthquake causes increased force in the surrounding area.

But things are quite different in some circumstances, such as the recent pair of earthquakes in California, a relatively large earthquake just being the forerunner for an even bigger event. While the difference between 7.1 and 6.4 may seem minor，magnitude is a logarithmic (对数的) scale. An increase of a unit of magnitude is about 32 times more energy, which means that the energy the second earthquake released is roughly 11 times that of the first one.

''Fortunately, no deaths or major injuries were reported, '' says Bohon, an earthquake geologist. ''It was in a fairly unpopulated area, although a lot of people felt it'' She suggests people who live in earthquake-prone (地震频发的)areas check how prepared they are for the next event. And she also hopes that the earthquake early warning system can play a good role in saving tens of thousands of lives and schools will popularize the knowledge of geological (地质的) disasters among students.

1.What can be learned from the first two paragraphs?

A.The first earthquake was predicted before its occurrence.

B.The two big earthquakes hit the same area within one day.

C.The aftershocks are even more dangerous than the first two earthquakes.

D.The second earthquake is the largest one in Southern California since 2000.

2.What does the third paragraph mainly talk about?

A.The introduction of Eastern California shear zone.

B.The forming process of the Little Lake fault zone.

C.The geological facts about the two big earthquakes.

D.The potential disasters caused by plate movement.

3.The recent two earthquakes represent an unusual circumstance in the way that.

A.a major earthquake is followed by a larger one

B.there is a minor difference in their magnitude

C.the two earthquakes release a similar amount of energy

D.a series of smaller earthquakes occur in the surrounding areas

4.What contributes to the good point of the two Southern California earthquakes?

A.The popularization of earthquake knowledge in schools.

B.Peopled good preparation made in advance.

C.Small populations in the earthquake-hit area.

D.The earthquake early warning system.

Answer

1.D

2.C

3.A

4.C

【解析】

本文是一篇新闻报道。加利福尼亚连续发生了两次大地震，所幸没有造成人员伤亡，地震地质学家建议地震高发区的人们应提前做好应对准备、学校应普及地质灾害的知识等。

1.细节理解题。根据第一段的Less than a day and a half later, a powerful magnitude7. 1 earthquake shook again. While earthquakes are not unexpected, the two most recent earthquakes are the largest that have struck this area in at least two decades.(不到一天半后，一次7.1级的地震再次发生了。虽然地震并不意外，但最近的两次地震是至少20年来袭击该地区最大的地震)可知，7.1级地震是南加州自2000年以来发生的最大的地震。D. The second earthquake is the largest one in Southern California since 2000. (第二次地震是南加州自2000年以来发生的最大的地震)符合以上说法，故选D项。

2.主旨大意题。根据第三段的They seemed to have occurred along the same set of faults lying in an area known as the Little Lake fault zone-in most circumstances, earthquakes hit in a familiar order: There’s a large earthquake followed by a series of smaller events. (他们似乎发生在同一组位于一个被称为the Little Lake fault zone的断层，大多数情况下，地震按一个熟悉的顺序发生：一个大地震后紧随一系列小规模的地震)可知，本段主要谈论与两次地震形成的地质事实，即发生在断层区域，且大小有相对的顺序性。C. The geological facts about the two big earthquakes. (与这两次地震相关的地质事实)符合以上说法，故选C项。

3.细节理解题。根据第四段的But things are quite different in some circumstances, such as the recent pair of earthquakes in California, a relatively large earthquake just being the forerunner for an even bigger event.(但有些情况就大不一样，比如最近发生在加州的两次地震，相对大的地震只是更大地震的前兆)可知，这两次地震的不同寻常之处在于：一次较大的地震后，又是一次级别更大的地震。A. a major earthquake is followed by a larger one (一次较大地震之后还有更大级别的地震)符合以上说法，故选A项。

4.细节理解题。根据最后一段的''Fortunately, no deaths or major injuries were reported, '' says Bohon, an earthquake geologist. ''It was in a fairly unpopulated area, although a lot of people felt it' ' (地震地质学家波斯福说：“幸运的是，没有死亡或者重大伤亡，这是一个少有人居住的地区，尽管很多人都感觉到了地震。”)可知，两次地震都发生在人口稀少的地区，所以未造成人员伤亡。C. Small populations in the earthquake-hit area. (地震发生区域人口稀少)符合以上说法，故选C项。