8．Coral reefs（珊 瑚 礁）are not just beautiful to look at，but also very useful．They shelter nearly 25% of ocean life and provide food for billions of people．However，like many other species，this amazing ecosystem（生态系统）is in danger of dying out!
There are two main reasons for the destruction-the rising carbon dioxide levels caused by global warming as well as human influences like bottom operation．While not much can be done about the former，the loss caused by the latter can be reduced．
Bottom operation involves dropping nets to the ocean bed and then dragging them up when filled with fish．This action damaged the ocean floor，causing the coral branches to separate from the reefs．While that is very discouraging，the good news is that if these branches are found quickly，they can be saved．At present，that work is being performed by volunteer divers．But the method has only limited success because they cannot stay long underwater，nor reach depths of over 200meters where some of the deep-sea coral grows．
However，this is not the case for Coralbots-the robots that can constantly seek out broken branches．A team of‘coralbots'，each individually working to simple rules will piece together'damaged bits of coral，allowing them to regrow．They are programmed to be able to distinguish between other things and the coral．The robots work together in groups，similar to bees．If one coralbot is damaged then the others will still be able to complete the task．
Dr Lea-Anne Henry said："The project of using coralbots offers us the possibility to restore（修复）the function of reefs．It is in the final stage of testing．Once ready，the researchers hope to build hundreds of them and use them effectively in the waters off Scotland and then hopefully in the oceans across the world．"
24．Which of the following is a cause of the danger that coral reefs are facing？D
A．The appearance of new creatures．
B．The seriously polluted sea water．
C．The activities of volunteer divers．
D．Human activities like bottom operation．
25．Compared with volunteer divers，coralbotsA．
A．can stay longer underwater B．must work as bees do
C．can distinguish what is coral D．can never be damaged
26．What does the underlined word"them"in the last paragraph refer to？A
A．Coralbots． B．Broken branches．
C．working bees． D．Bits of coral．
27．We can infer from the passage thatB．
A．bottom operation has affected most underwater creatures
B．broken branches of coral can regrow if saved in time
C．hundreds of the coralbots have worked well in the oceans
D．with the coralbots all damaged coral reefs can be restored．
分析 本文主要介绍了珊瑚礁所面临的问题以及应对的方法．珊瑚礁由于全球变暖以及人类的一些海底作业而濒临灭绝．对此，Coral bots却是一个挽救珊瑚礁的好帮手，它可以长时间呆在水下以帮助受损的珊瑚礁重新生长．
解答 24---27 DAAB
【解析】试题分析：
24．答案D．细节理解题．根据第二段的There are two main reasons for the destruction-the rising carbon dioxide levels caused by global warming as well as human influences like bottom operation．可知有两个原因导致珊瑚礁面临灭绝．故选择D，指人类海底作业导致珊瑚礁面临灭绝．
25．答案A．细节理解题．根据第三段最后的But the method has only limited success because they cannot stay long underwater，nor reach depths of over 200 meters where some of the deep-sea coral grows．以及第四段的However，this is not the case for Coral bots可知，志愿者不能长时间呆在水下，但是Coral bots可以，故选择A，指它可以长时间呆在水下．
26．答案A．词语辨析题．本题考查代词的指代意义．根据下文的use them effectively in the waters off Scotland and then hopefully in the oceans across the world可知，这里的them指代的是上文提到的Coral bots，因为要用这样东西来修复珊瑚礁．故选择A．
27．答案B．细节理解题．根据第三段the good news is that if these branches are found quickly，they can be saved可知，珊瑚礁如果被损后再短时间内修复还是可以的．故选择B．选项A未涉及；根据最后一段的It is in the final stage of testing可知选项C错误；而根据then hopefully in the oceans across the world可知，修复珊瑚礁只是有希望，而不是绝对会被修复，故选项D错误．
点评 阅读理解解题技巧：1．迅速将整篇文章分解，理出文章结构；2．迅速抓住文章叙述的主题；3．迅速找出各部分的中心意思，并找出表达中心意思的句子．
