第六部分 完形填空（共四篇）
第十四篇
Sharks Perform a Service for Earth's Waters
It is hard to get people to think of sharks as anything but a deadly enemy1. They are thought to 1 people frequently. But these fish2 perform a 2 service for earth's waters and for human beings. Yet business and sport fishing3 are threatening their 3 Some sharks are at risk of disappearing from 4
Warm weather may influence both fish and shark activity. Many fish swim near coastal areas 5 their warm waters. Experts say sharks may follow the fish into the same areas, 6 people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person 7 a sea animal, such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the 8 when sharks are looking for food. Experts also say that bright colors and shiny jewelry
may cause sharks to attack.
A shark has an extremely good sense of smell4' It can find small amounts of substances in water, such as blood, body liquids and 9 produced by animals. These powerful 10 help sharks fred their food. Sharks eat fish, any 11 sharks, and plants that live in the ocean.
Medical researchers want to learn more about the shark's body defense, and immune 12 against disease. Researchers know that sharks 13 quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the world's 14 They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too 15 This protects the plants and other forms of life that exist in the oceans.
詞匯:
purposely adv.故意地，蓄意地 immune adj.免疫的
charge v.（向……）沖（過去） jewelry n.珠寶
seal n. 海豹
注釋：
1．It is hard to get people tO think of sharks as anything but a deadly enemy：要讓人們相信鯊魚不是(人類的)死敵不是一件容易的事。anything but意為“決不，遠(yuǎn)非”，如：His performance in London is anything but a success．(她在倫敦的演出完全不成功。)
2．these fish：這些魚(指鯊魚)。fish單復(fù)數(shù)同形，如：0ne fish，two fish，many fish(見第二段第一句)。
3．sport fishin9：捕魚運(yùn)動(dòng)。
4．sense of smell：嗅覺
練習(xí):
1. A attack B meet C love D visit
2. A terrible B eatable C valuable D possible
3. A source B existence C friends D fish
4. A Space B Sky C Land D Earth
5. A because B since C because of D by reason that
6. A whose B which C that D where
7. A to B for C like D with
8. A times B places C seas D oceans
9. A sciences B mathematics C chemicals D physics
10. A feelings B senses C touches D tastes
11. A those B these C another D other
12. A systems B processes C ideas D circles
13. A recover B reform C return D rely
14. A rivers B oceans C forests D mountains
15. A weak B little C few D great
答案與題解：
1．A本題應(yīng)選擇attack，因?yàn)榈谝痪湔f到：人們認(rèn)為鯊魚是a deadly enemy，也就是說鯊魚會(huì)對(duì)人類造成傷害。第二句是對(duì)deadly enemy的具體說明。其他的三個(gè)選項(xiàng)meet，love，visit都不合適，love與上下文意思相反，meet和visit與上下文意思不符。
2．C空格2所在的句子由but連接，所以該句子表達(dá)的意思一定與第二句相反。第二句對(duì)
鯊魚的評(píng)價(jià)是負(fù)面的，填入空格2的詞應(yīng)該是正面的。四個(gè)選項(xiàng)中只有valuable符合這一條件，所以是答案。
3．B第三句說到鯊魚有益于“waters and human beings”，第五句又說到鯊魚瀕臨滅絕的危險(xiǎn)。根據(jù)上下文的意思，threatening(威脅)到它們的應(yīng)該是existence(生存)。其他的三個(gè)選項(xiàng)source，friends，fish都不合適，與上下文意思沒有聯(lián)系。
4．D如果鯊魚消失，從什么地方消失呢?當(dāng)然從earth(地球)上消失。從space(宇宙空間)、sky(天空)中消失，或從land(陸地)上消失，都有悖常理。
5．C四個(gè)選項(xiàng)的意思都是“因?yàn)?ldquo;，但是從用法上分析，because、since和by reason that之后要接句子，because of之后接名詞或名詞短語。their warm waters是名詞短語，所以要選用because of。
6．D“…people also swim”明顯是定語從句，其先行詞是表示地點(diǎn)的名詞area，所以要選關(guān)系副詞where．。
7．B從上下文判斷，本句的意思是：鯊魚將人錯(cuò)認(rèn)為是海洋動(dòng)物。而“將……錯(cuò)認(rèn)為是”的英語表達(dá)是mistake…for，所以本題的答案是選項(xiàng)B。
8．A本段的意思是：鯊魚并非故意襲擊人類。人們認(rèn)為，由于鯊魚將人錯(cuò)認(rèn)為是海獅等海洋動(dòng)物，在饑餓時(shí)才襲擊人類。日出和日落時(shí)，正是鯊魚饑腸轆轆的時(shí)候，人們不應(yīng)該出海游泳�？崭�8填入的詞應(yīng)該與時(shí)間有關(guān)，所以times是答案，而與地點(diǎn)有關(guān)的選項(xiàng)(places seas和oceans)與上下文意思脫節(jié)。
9．C本段第一、二句是說，鯊魚的嗅覺特別靈敏，能嗅到海水中存在的極為微量的氣味。作者舉了三個(gè)物質(zhì)：血、體液和化學(xué)品�？崭�9要填入表示物質(zhì)的名詞。四個(gè)選項(xiàng)中惟一表達(dá)物質(zhì)的詞是chemicals(化學(xué)品)。所以chemicals是答案，而其它三個(gè)選項(xiàng)與學(xué)科有關(guān)，脫離了上下文的意思，不是本題的答案。
10．B在第一、二句意思的基礎(chǔ)上，作者進(jìn)一步說明，靈敏的嗅覺有助于鯊魚找到食物。所以本題的答案是選項(xiàng)D的senses，因?yàn)閒eelings，touches和tastes都與smells無關(guān)。
11．D 本句的中心詞是復(fù)數(shù)的sharks，another所修飾的名詞一般是單數(shù)，所以不會(huì)是答案。these和those是表特指的代詞，指代前面出現(xiàn)過的名詞。由于前面沒有先行詞，所以也不可能是答案。剩下的other是答案，any other sharks的說法也合乎英語的用法。
12．A從上下文判斷，醫(yī)學(xué)研究人員想要更多了解的是“身體抗病system(系統(tǒng))”，不會(huì)是
“身體抗病idea(思想)”、“身體抗病工作(work)”或“身體抗病circle(周期)”。
13．A本段最后一句的意思是：醫(yī)學(xué)研究人員研究鯊魚的目的是為了找到一種人類抗病的方
法。所以空格l3所在句子的意思應(yīng)該是recover(quickly from injuries)�？茖W(xué)家想要探索的應(yīng)該是有關(guān)受傷鯊魚recover quickly from injuries的秘密，而reform(改造)、return(回歸)和rely(依靠)只是與答案recover詞形上有點(diǎn)相似而已，其意思與上下文的意思風(fēng)馬牛不相及。
14．B 從上下文判斷，鯊魚的存在能使0ceans得益。鯊魚不生活在rivers、forests或mountains中，所以，這三個(gè)選項(xiàng)不會(huì)是答案。
15．D本段的其余三句都是說明為什么鯊魚有益于海洋。它們吃海洋動(dòng)物，結(jié)果使得海洋中
的動(dòng)物數(shù)量不會(huì)過多。weak、little、few都與上面表達(dá)的意思相反，所以，只有g(shù)reat是答案。
