Question

17．There are thousands of coral reefs（珊瑚礁） in the world； Unfortunately，however，they are now in serious danger．More than one-third are in such bad shape that they could die within ten years．（36）BHere are the three main causes discovered．
The first cause is pollution on land．The pollutants run with rainwater into rivers and streams，which carry the poisons into the ocean．（37）ESo they will be easily infected（感染） with diseases．
   （38）AHigher ocean temperatures kill the important food source（来源） for the coral-the algae，the tiny greenish-gold water plants that live on coral．（39）GThis process has happened more and more frequently in recent years．
The last factor contributing to the disappearance of coral reefs is people．People sometimes crash into reefs with their boats，breaking off large blocks of coral．（40）CMoreover，some people even break coral off to collect for souvenirs since it is so colorful and pretty．
 
A．Global warming is another reason．
B．Many might not even last that long!
C．Divers who walk on reefs can also do serious damage．
D．Reefs provide a home for 25% of the fish in the ocean．
E．Chemicals from the poisons kill reefs or make them weak．
F．Steps must be taken now to stop over-fishing and pollution of the oceans．
G．When the algae die，the coral loses its color and it also dies in the end．

Answer 1

分析 本文主要介绍了珊瑚礁正处于严重的危险中，有的可能在未来十几年中就死亡了．文章讲述了引起珊瑚礁死亡的三个主要原因：1、土地污染；2、全球变暖；3、人为因素．

解答 36．B细节理解题．前面说they are now in serious danger．More than one-third are in such bad shape that they could die within ten years．后面说Here are the three main causes discovered．珊瑚礁现在正处于严重的危险中，超过1/3的可能在十年内死亡．由此推知，该处讲的是许多甚至可能不会持续那么久．故选B．
37．E段落大意题．本段主要介绍了有毒物质对珊瑚礁的危害．故选E．
38．A段落大意题．本段主要介绍了海洋温度的上升对珊瑚礁的影响．由此推知，该处讲的是全球变暖是另一个原因．故选A．
39．G逻辑推理题．前面说Higher ocean temperatures kill the important food source（来源） for the coral-the algae，the tiny greenish-gold water plants that live on coral．较高的海洋温度杀死令了珊瑚的重要食物来源--珊瑚藻．后面说This process has happened more and more frequently in recent years．这个过程在近年里发生的越来越频繁．由此推知，该处讲的是当海藻死了，珊瑚最后也会死．故选G．
40．C段落大意题．本段主要介绍了人为因素对珊瑚礁的影响．故选C．

点评 七选五是一类完成性阅读．在题型上与完型填空很类似．解题时，要在理解文章整体的情况下，充分考虑语境和空格前后的句子，注意句子之间的逻辑关系，尤其要学会把握信息词（选项中出现的与文章中相同或相近的词），快速准确的选出最符合文章原意的答案．