20.Some scientists say that animals in the oceans are increasingly threatened by noise pollution caused by human beings.
The noise that affects sea creatures comes from a number of human activities.It is caused mainly by industrial underwater explosions,ocean drilling,and ship engines.Such noises are added to natural sounds.These sounds include the breaking of ice fields,underwater earthquakes,and sounds made by animals themselves.
Decibels (分貝) measured in water are different from those measured on land.A noise of one hundred and twenty decibels on land causes pain to human ears.In water,a decibel level of one hundred and ninety-five would have the same effect.
Some scientists have suggested setting a noise limit of one hundred and twenty decibels in the oceans.They have observed that noises at that level can frighten and confuse whales(鯨魚).
A team of American and Canadian scientists discovered that louder noises can seriously injure some animals.
The research team found that powerful underwater explosions were causing whales in the area to lose their hearing.This seriously affected the whales'ability to exchange information and find their way.Some of the whales even died.The explosions had caused their ears to bleed and become infected(被感染的).
Many researchers whose work depends on ocean sounds are against a limit of one hundred and twenty decibels.They say such a limit would mean an end to important industrial and scientific research.
Scientists do not know how much and what kinds of noises are harmful to ocean animals.However,many scientists don't think that noise is a greater danger than they believed.They want to prevent noises from harming creatures in the ocean.
26.According to the passage,which of the following is increasingly dangerous to sea creatures?C
A.The sound of ______ cars.
B.The sound of voices.
C.Man-made noise pollution.
D.The sound of steps.
27.According to the passage,natural sounds include all of the following EXCEPTB.
A.sounds made by animals themselves B.ocean drilling
C.underwater earthquakes D.the breaking of ice fields
28.Which of the following is discussed in the third paragraph?A
A.The same noise level produces a different effect on land and in the ocean.
B.Different places may have different types of noises.
C.The decibel is not a right unit (單位) for measuring underwater noise.
D.Different ocean animals may have different reactions to noises.
29.Which of the following is true of whales?D
A.They won't be confused by noises.
B.They are deaf to noises.
C.Their ability to reproduce will be lowered by high-level noises.
D.Their hearing will be damaged by high-level noises.
30.According to the passage,what will scientists most probably do in the future?B
A.They will work hard to reduce ocean noise pollution.
B.They will protect animals from harmful noises.
C.They will try to set a limit of 120decibels.
D.They will study the effect of ocean noise pollution.
分析 本文敘述了研究表明噪音污染引起了海洋生物的危險(xiǎn),科學(xué)家將來要采取措施拯救海洋生物,阻止噪音對海洋生物的傷害,提醒我們也要意識到保護(hù)海洋生物的重要性.
解答 26.C.細(xì)節(jié)理解題.由第一段Some scientistssay that animals in the oceans are increasingly threatened by noise pollutioncaused by human beings.可知噪音污染引起了海洋生物的危險(xiǎn),故選C.
27.B.細(xì)節(jié)理解題.由第二段These soundsinclude the breaking of ice fields,underwater earthquakes,and sounds made byanimals themselves.可知ocean drilling不是自然的聲音,故選B.
28.A.段落大意題,根據(jù)Decibels (分貝) measured in water are different from those measuredon land.這是中心句可知同一種噪音在陸地和水面產(chǎn)生的效果是不一樣,故選A.
29.D.推理判斷題.根據(jù)第六段The researchteam found that powerful underwater explosions were causing whales in the areato lose their hearing.可知水下巨大的爆炸聲會使鯨失去聽力,故選D.
30.B.推理判斷題.由文章的最后一句話They wantto prevent noises from harming creatures in the ocean.可知科學(xué)家將來要采取措施阻止噪音對海洋生物的傷害,故選B.
點(diǎn)評 考察學(xué)生的細(xì)節(jié)理解和推理判斷能力,做細(xì)節(jié)理解題時(shí)一定要找到文章中的原句,和題干進(jìn)行比較,再做出正確的選擇.在做推理判斷題不要以個(gè)人的主觀想象代替文章的事實(shí),要根據(jù)文章事實(shí)進(jìn)行合乎邏輯的推理判斷.