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（來源） 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 作者通過這篇文章介紹了全球的海洋珊瑚礁正在受到破壞，文章主要介紹了對珊瑚造成危害的不同的原因．

解答 16．B：考查上下文串聯(lián)和句意理解：根據(jù)上文：More than one-third are in such bad shape that they could die within ten years．可知超過三分之一的珊瑚礁會在十年之內(nèi)死去，故選B．
17．E：考查上下文串聯(lián)和句意理解：根據(jù)上文：The pollutants run with rainwater into rivers and streams，which carry the poisons into the ocean．可知來自毒品的化學物質(zhì)會殺了珊瑚礁或讓它們變得虛弱．故選E．
18．A：考查上下文串聯(lián)和句意理解：根據(jù)下文：Higher ocean temperatures kill the important food source（來源） for the cora可知全球氣溫變暖是另外一個問題，故選A．
19．G：考查上下文串聯(lián)和句意理解：根據(jù)上文：the algae，the tiny greenish-gold water plants that live on coral．可知當水藻死了，珊瑚會失去顏色，最終死亡，故選G．
20．：C  考查上下文串聯(lián)和句意理解：根據(jù)上文：The last factor contributing to the disappearance of coral reefs is people．可知在礁石上行走的潛水員也會造成傷害．故選C．

點評 考查學生的細節(jié)理解和推理判斷能力．做細節(jié)理解題時一定要找到文章中的原句，和題干進行比較，再做出正確選擇．在做推理判斷題時不要以個人的主觀想象代替文章的事實，要根據(jù)文章事實進行合乎邏輯的推理判斷．