Everyone has heard of the San Andreas fault , which constantly threatens California and the West Coast with earthquakes. But how many people know about the equally serious New Madrid fault in Missouri? Between December of 1811 and February of 1812, three major earthquakes occurred, all centered around the town of New Madrid, Missouri, on the Mississippi River. Property damage was severe. Buildings in the area were almost destroyed. Whole forests fell at once, and huge cracks opened in the ground, allowing smell of sulfurto filter upward. The Mississippi River itself completely changed character, developing sudden rapids and whirlpools. Several times it changed its course, and once, according to some observers, it actually appeared to run backwards.Few people were killed in the New Marid earthquakes, probably simply because few people lived in the area in 1811; but the severity of the earthquakes are shown by the fact that the shock waves rang bells in church towers in Charleston, South Carolina, on the coast. Buildings shook in New York City, and clocks wer stopped in Washington, D.C. Scientists now know that America s two major faults are essentially different. The San Andreas is a horizontal boundary between two major land masses that are slowly moving in opposite directions. California earthquakes result when the movement of these two masses suddenly lurches forward. The New Madrid fault, on the other hand, is a vertical fault; at some points, possibly hundreds of millions of years ago, rock was pushed up toward the surface, probably by volcanoes under the surface. Suddenly, the volcanoes cooled and the rock collapsed, leaving huge cracks. Even now, the rock continues to settle downwards, and sudden sinking motions trigger earthquakes in the region. The fault itself, a large crack in this layer of rock, with dozens of other cracks that split off from it, extends from northeastArkansas through Missouri and into southern lllinois. Scientists who have studied the New Madrid fault say there have been numerous smaller quakes in the area since 1811; these smaller quakes indicate that larger ones are probably coming, but the scientists say have no method of predictingwhen a large earthquake will occur. 11. This passage is mainly about . A)the New Madrid fault in Missouri B)the San Andreas and the New Madrid faults C)the causes of faults D)current scientific knowledge about faults 12. The New Madrid fault is . A) a horizontal fault B) a vertical fault C) a more serious fault than the San Andreas fault D) responsible for forming the Mississippi River 13. We may conclude from the passage that . A) it is probably as dangerous to live in Missouri as in California B) the New Madrid fault will eventually develop a mountain range in Missouri C) California will become an island in future D) A big earthquake will occur to California soon 14. This passage implies that . A) horizontal faults are more dangerous than vertical faults. B) Vertical faults are more dangerous than horizontal faults C) Earthquakes occur only around fault areas D) California will break into pieces by an eventual earthquake 15. As used in the first sentence of the fourth paragraph, the word essentially means . A) greatly C) basically B) extremely D) necessarily
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不能连词数字的几种常见情况
英语冠词的三种特殊位置
定冠词的五种特指用法
数词的分类及用法简介
a与an的区别|易错说明
常用数学公式的表示方法
数字习语:at sixes and sevens
冠词在句中的特殊位置
数词可与coffee连用吗
长度等的表示方法
如何用英语编号
含有数字one的英语成语
定冠词的考点性用法
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英语省略冠词的四种重要情形
含有数字two的英语成语
hundred, thousand和million的用法说明
有关dozen与score的用法说明
基数词及序数词重要用法
不定冠词的四个基本用法
有关数词用法的几个易错点
不定冠词与one的五点区别
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一道易错冠词考题
dozen,score,hundred,thousand,million用法要点
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“三餐饭”冠词使用规律
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