Thevolcanoisoneofthemostsurprisingfrighteningthingsofnature．Maybeyouhaveseenpicturesofthese“fireworks”ofnature．Sometimeswhenavolcanoeruptsaverylargewallofmeltedrockm

Question

　　The volcano is one of the most surprising frightening things of nature．Maybe you have seen pictures of these“fireworks”of nature．Sometimes when a volcano erupts a very large wall of melted rock moves down the side of a mountain．It looks like a“river of fire”．Sometimes volcanoes explode throwing the melted rock and ashes high into the air．But where does this melted rock come from?

　　The earth is made up of many layers(层)．The top layer that we see is called the crust．Under the crust are many layers of hard rock．But far far beneath the crust the rock is so hot that it is soft．In some places it even melts．The melted rock is called magma．Sometimes the magma breaks out to the surface through cracks(裂缝)in the crust．These cracks are volcanoes．

　　Most people think of mountains when they think of volcanoes．But not every mountain is a volcano．A volcano is simply the opening in the earth from which the magma escapes．The hot magma or lava as it is called cools and builds up on the surface of the earth．Over thousands of years this pile of cooled lava can grow to be very very big．For example the highest mountain in Africa Kilimanjaro is a volcano．It rises more than 16 000 feet above the ground around it．

(1)

The underlined word“erupts”means ________．
[　　]
A．	moves down
B．	breaks away
C．	builds up
D．	suddenly throws out lava

(2)

Which words in the passage have the same meaning as“melted rock”?
[　　]
A．	volcano and crust
B．	crust and hard rock
C．	magma and lava
D．	volcano and magma

(3)

Which is the correct order of the layers of the earth(beginning with the top layer)?
[　　]
A．	Crust→hard rock→magma→soft rock．
B．	Crust→hard rock→soft rock→magma．
C．	Magma→soft rock→hard rock→crust．
D．	Volcano→cracks→magma→crust．

(4)

The best title of the passage should be ________．
[　　]
A．	The Volcano
B．	Kilimanjaro Volcano
C．	The Mountains
D．	The Melted Rock

Answer 1

答案：1．D;2．C;3．B;4．A;
解析：
(1) 词义题．火山爆发时熔岩有时顺山坡流下，有时被抛向空中． (2) 词义题．文章第二段中说到：In some places it even melts．The melted rock is called magma．另外文章第三段中也说到：The hot magma or lava as it is called…由此可知答案为C． (3) 细节题．第二段提到地壳最上层为crust，在crust之下是hard rock，其次是soft rock，最后是magma． (4) 主旨题．从整篇文章可以看出该文主要介绍火山的形成过程．