Question

7．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．（16）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．（17）ESo they will be easily infected with diseases．（18）A Higher ocean temperatures kill the important food source（来源） for the coral-the algae（海藻），the tiny greenish-gold water plants that live on coral．（19）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．（20）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 作者通过这篇文章介绍了全球的海洋珊瑚礁正在受到破坏，文章主要介绍了对珊瑚造成危害的不同的原因．

解答 16．B：考查上下文串联和句意理解：根据上文：More than one-third are in such bad shape that they could die within ten years．可知超过三分之一的珊瑚礁会在十年之内死去，故选B．
17．E：考查上下文串联和句意理解：根据上文：The pollutants run with rainwater into rivers and streams，which carry the poisons into the ocean．可知来自毒品的化学物质会杀了珊瑚礁或让它们变得虚弱．故选E．
18．A：考查上下文串联和句意理解：根据下文：Higher ocean temperatures kill the important food source（来源） for the cora可知全球气温变暖是另外一个问题，故选A．
19．G：考查上下文串联和句意理解：根据上文：the algae，the tiny greenish-gold water plants that live on coral．可知当水藻死了，珊瑚会失去颜色，最终死亡，故选G．
20．：C  考查上下文串联和句意理解：根据上文：The last factor contributing to the disappearance of coral reefs is people．可知在礁石上行走的潜水员也会造成伤害．故选C．

点评 考查学生的细节理解和推理判断能力．做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确选择．在做推理判断题时不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．