A) Because they provide a means of living and source of food for human beings.
B) Because they provide a tourist destination for human beings.
C) Because they provide a place for human beings to fish.
D) Because they provide a kind of entertainment for human beings.
3. If in a healthy state, coral reefs can .
A) stop tsunamis and storm events from attacking the coastlines
B) protect coastlines from the damage of extraordinary waves
C) stop people from fishing ear the coral reefs
D) protect coastlines from people's damage
4. What is said about human's activity as littering plastic bags and bottles?
A) It ca badly damage the coral reefs ear the coastline.
B) It can have impact on tourism of the developed countries.
C) It ca badly damage people's life near the coastline.
D) It ca pollute the ocean and influence tourism.
5. When mercury falls into the ocean, it was converted to a chemical of more harmful nature that can endanger .
A) unborn babies and young children
B) adult women
C) the environment of the ocean
D) the coral reefs
6. Carbonic acid has the most serious impact on .
A) the human being
B) shell fish and star fish
C) tunas and sharks
D) marine mammals
7. People bomb certain area of the sea and the killed fish floating on the sea surface
A) can be collected easily
B) can harm the ocean
C) can pollute the environment
D) can damage people's health
8. We ca wither find alterative energy sources or make better use of fossil fuels to reduce____________.
9. We are now researching to find alternative fuels that are more environmentally friendly and _________________.
10. We should protect the marine creatures as creatures themselves that have rights for survival, not simply as useful _______________.
文章梗概：
本文介绍了海洋及海洋生物的作用及其所受到的危害。首先介绍海洋的作用——提供食物、旅游资源，海洋生物对海岸的保护。之后阐述了过度捕鱼造成的危害。接下来谈到了各种污染物对海洋及生物的影响，以及对人类的危害。最后指出我们应该保护海洋资源，确保海洋生物的生存。
答案解析：
1.由题干关键词Coral reefs和supports. . . animals and plants定位至第三段第三句They support as many as 1 million species of animals and plants, but only a small fraction have been described. 珊瑚礁供养着多达100万种动植物，但其中人们描述的仅有一小部分。由此可知选项C)正确。
2. 由题干关键词essential to human beings定位至第四段第三句A majority of people make their living fishing near coral reefs and an even larger part of population enjoys eating some of the catch. 选项A)是对该句的同义转述，故为正确答案。
3. 由题干关键词healthy state和coral reefs定位至第五段第三句Healthy reefs protect coastlines from the damage of massive waves. 健康的珊瑚礁可以保护海岸不受巨浪冲击的伤害。这说明珊瑚礁能降低风暴的危害程度，而A)说珊瑚礁能阻止风暴侵袭是错误的;C)和D)文中并未提及;B)中的extraordinary一词和massive同义，故为正确答案。
4. 由题干关键词littering plastic bags and bottles定位至第六段,该段主要阐述人类随意丢弃垃圾的行为会污染海洋，影响旅游业，尤其是第三世界国家的旅游业，却没有提及这种行为对珊瑚礁的影响。因此答案为D)。
5. 由题干关键词mercury和harmful定位至第七段倒数第三句It is this type of mercury that can be harmful to unborn babies and young children. 是这种水银可能对未出生的婴儿和幼儿有害。A)是该句的同义转述，故正确。
6. 由题干关键词carbonic acid定位至第九段第三句Sea creatures such as corals, shell fish, … because higher levels of acidity makes it difficult for them to form and maintain their hard calcium carbonate skeletons and shells. 像珊瑚、贝类动物、海胆和海星这样的海洋生物容易受到最大的伤害，因为酸量较高的话会使它们难以形成和保养自身坚硬的碳酸钙骨骼和外壳。因此答案为B)。
7. 由题干关键词bomb certain area of the sea定位至倒数第四段倒数第三句This technique involves bombs that are detonated at sea in the hopes that the fish killed float to the surface for easy collection.意思是这项技术包含在海里实施爆炸，以此希望漂浮在海面上被炸死的鱼可以轻易地被收集起来。 由此可知A)正确。
8. 由题干关键词fossil fuels定位至倒数第三段第三句Two effective techniques for limiting CO2 emissions would be, (1) to replace fossil fuels with energy sources that do not emit CO2, and (2) to use fossil fuels more efficiently.由此可见，题干是对这句话的同义转述，据此，答案应为CO2 emissions.
9. 由题干关键词alternative fuels和more environmentally friendly定位至倒数第二段最后一句Until research comes up with less expensive alternative fuels, fossil fuels will continue to be used as the world's primary energy source. 据此，答案应为less expensive.
10. 由题干关键词protect the marine creatures定位至最后一段最后一句It is important to protect existing marine habitats, not only to protect a major resource of everything from food to tourism to coastal protection…. 无疑，protect后面就是答案，但是应该根据题干的含义进行简化。经分析可知，与海洋生物自身的生存相对比,它们作为食品、旅游和海岸保护资源都是从人类角度出发的，据此，可以把这些作用总结为resource to human being.