Mostearthquakesoccurwithintheupper15milesoftheearth’ssurface.Butearthquakescananddooccuratalldepthstoabout460miles.Theirnumberdecreasesasthedepthincreases.Atabout460milesoneearthquakeoccursonlyeveryf

Question

Most earthquakes occur within the upper 15 miles of the earth’s surface. But earthquakes can and do occur at all depths to about 460 miles. Their number decreases as the depth increases. At about 460 miles one earthquake occurs only every few years. Near the surface earthquakes may run as high as 100 in a month but the yearly average does not vary much. In comparison with the total number of earthquakes each year the number of disastrous earthquakes is very small.[JP]

The extent of the disaster in an earthquake depends on many factors. If you carefully build a toy house with an erect set it will still stand no matter how much you shake the table. But if you build a toy house with a pack of cards a slight shake of the table will make it fall. An earthquake in Agadir Morocco was not strong enough to be recorded on distant instruments but it completely destroyed the city. Many stronger earthquakes have done comparatively little damage. If a building is well constructed and built on solid ground it will resist an earthquake. Most deaths in earthquakes have been due to faulty building construction or poor building sites. A third and very serious factor is panic. When people rush out into narrow streets more deaths will result.

The United Nations has played an important part in reducing the damage done by earthquakes. It has sent a team of experts to all countries known to be affected by earthquakes. Working with local geologists and engineers the experts have studied the nature of the ground and the type of most practical building code for the local area. If followed these suggestions will make disastrous earthquakes almost a thing of the past.

There is one type of earthquake disaster that little can be done about. This is the disaster caused by seismic sea waves or tsunamis. (These are often called tidal waves but the name is incorrect. They have nothing to do with tides.)

In certain areas earthquakes take place beneath the sea. These submarine earthquakes sometimes give rise to seismic sea waves. The waves are not noticeable out at sea because of their long wave length. But when they roll into harbors they pile up into walls of water 6 to 60 feet high. The Japanese call them “tsunamis” meaning “harbor waves” because they reach a sizable height only in harbors.

Tsunamis travel fairly slowly at speeds up to 500 miles an hour. An adequate warning system is in use to warn all shores likely to be reached by the waves.

But this only enables people to leave the threatened shores for higher ground. There is no way to stop the oncoming wave.

 

65. Which of the following CANNOT be concluded from the passage?

A. The number of earthquakes is closely related to depth.

B. Roughly the same number of earthquakes occur each year.、

C. Earthquakes are impossible at depths over 460 miles.

D. Earthquakes are most likely to occur near the surfaces.

66. The destruction of Agadir is an example of_____.

A. faulty building construction                        B. an earthquake’s strength

C. widespread panic in earthquakes                 D. ineffective instruments

67. The United Nations’ experts are supposed to_____.

A. construct strong buildings                         B. put forward proposals

C. detect disastrous earthquakes                     D. monitor earthquakes

68. The significance of the slow speed of tsunamis is that people may_____.

A. notice them out at sea                               B. find ways to stop them

C. be warned early enough                             D. develop warning systems

Answer 1

65. C 可用排除法来找出此题的答案。题干要求找出无法从文章中得出结论的一项。根据文章第一段第一句到第三句可知”随着深度的增加，地震的数量随之减少”，可得出结论选项A”地震的数量和深度密切相关”，故排除。根据文章第一段第五行”…  in a month but the yearly average does not vary much.”（接近地表处地震的发生频率可高达每月一百多次，但是年平均地震数量却变化不大。）可排除选项B Roughly the same number of earthquakes occur each year.（每年发生的地震数量大致相同）；根据文章第一段可得出以下结论：地震主要发生在离地表十五公里的范围之内，尽管深达460公里的深处也有地震发生，但是每隔几年才发生一次。故可排除选项D Earthquakes are most likely to occur near the surfaces.（地震主要发生在地表处）。综上可知，选项 C 为正确答案。66. A 文章第二段首先举例说明运用不同的建筑方法和材料所修建的房屋的抗震能力是不同的，进而就提到了发生在摩洛哥Agadir的地震虽然震级不大，却摧毁了整个城市，而许多更强烈的地震所造成的损失却很小，由此作者得出结论：如果建筑物修建得好并且建在坚固的地面上，那么它就能抵御地震；地震中大多数的死亡是由于不良的建筑结构或不当的建筑地点造成的。由此可知作者引用摩洛哥的Agadir的毁灭主要是要说明不良的建筑结构（faulty building construction），故选项A为正确答案。67. B 根据文章第三段可知，联合国在地震减灾方面起到了非常重要的作用，它派出了许多地震专家到饱受地震袭扰的国家，与当地的地质学家和工程师一起研究当地的地质构造及适合当地的实用的建筑法规，并且如果这些专家提出的建议得到采纳，灾难性的地震就会成为历史。因此这四个选项中，最合适的是B put forwardproposals “提出建议”，故其为正确答案。 68. C 根据文章最后一段，海啸的移动速度缓慢，使人们得以及早发现，以提前向沿岸的居民发出警告，离开海边到高地去，但是人们却无法阻止到来的巨浪。故选项C be warned early enough为正确答案。