Scattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They drift about lazily with the currents, providing a basic food for many larger animals. Plankton has been described as the equivalent of the grasses that grow on the dry land continents, and the comparison is an appropriate one. In potential food value however, plankton far outweighs that of the land grasses. One scientist has estimated that while grasses of the world produce about 49 billion tons of valuable carbohydrates each year. The seas plankton generates more than twice as much.
Despite its enormous food potential, little effort was made until recently to farm plankton as we farm grasses on land. Now marine scientists have at last begun to study this possibility, especially as the seas resources loom even more important as a means of feeding an expanding world population.
No one yet has seriously suggested that planktonburgers may soon become popular around the world. As a possible farmed supplementary food source, however, plankton is gaining considerable interest among marine scientists.
One type of plankton that seems to have great harvest possibilities is a tiny shrimplike creature called krill. Growing to two or three inches long, krill provide the major food for the giant blue whale, the largest animal ever to inhabit the Earth. Realizing that this whale may grow 100 feet and weigh 150 tons at maturity, it is not surprising that each one devours more than one ton of krill daily.
Krill swim about just below the surface in huge schools sometimes miles wide, mainly in the cold Antarctic. Because of their pink color, they often appear as a solid reddish mass when viewed from a ship or from the air. Krill are very high in food value. A pound of these crustaceans contains about 460 caloriesabout the same as shrimp or lobster, to which they are related.
If the krill can feed such huge creatures as whales, many scientists reason, they must certainly be contenders as new food source for humans.
1.Which of the following best portrays the organization of the passage?
A.The author presents the advantages and disadvantages of plankton as a food source.
B.The author quotes public opinion to support the argument for farming plankton.
C.The author classifies the different food sources according to amount of carbohydrate.
D.The author makes a general statement about plankton as a food source and then moves to a specific example.
2.According to the passage, why is plankton regarded to be more valuable than land grasses?
A.It is easier to cultivate.
B.It produces more carbohydrates.
C.It does not require soil.
D.It is more palatable.
3.Why does the author mention planktonburgers?
A.To describe the appearance of one type of plankton.
B.To illustrate how much plankton a whale consumes.
C.To suggest plankton as a possible food sources.
D.To compare the food values of beef and plankton.
4.What is mentioned as one conspicuous feature of krill?
A.They are the smallest marine animals.
B.They are pink in color.
C.They are similar in size to lobsters.
D.They have grass like bodies.
5.The author mentions all of the following as reasons why plankton could be considered a human food source except that it is ___.
A.high in food value.
B.in abundant supply in the oceans.
C.an appropriate food for other animals.
D.free of chemicals and pollutants.
答案:DBCBD
记住10部经典电影的10句爱情箴言
唯美如画,细腻如诗的十部经典电影
温暖冬日心情的10部电影(组图)
十部值得期待的好莱坞冬季档电影
米高梅破产:怀念十大经典佳片
《阿凡达》删节片段首曝光
【秘籍】《哈利波特》咒语大全(中英)
《人物》评2010最性感男士 瑞安雷诺兹夺魁
《暮光之城4》会更加香艳&《哈利波特》男演员集体卷入"
魔法三人组《哈利•波特》十年友谊剧情回顾
美国电影学会(AFI)公布2010十佳电影
十部教你如何花钱的电影
华纳经久不衰的经典形象盘点
女王亲临纳尼亚首映 魔法姐妹雪天性感抢镜
2010年度盘点之年度最佳喜剧TOP10
秋日推荐:属于女人的11部经典电影
莉顿-梅斯特透露《绯闻女孩》六季终结
英剧:《唐顿庄园》Downton Abbey第4集花絮
14部适合冬日欣赏的温情电影
"老友"重聚大银幕 粉丝只要怀旧不
《创》伦敦首映 沧桑布里吉斯揽美艳王尔德
GossipGirl第四季第8集剧情预告 诡计妹露馅
Teri Hatcher(Susan May
《哈利-波特》电影对原著删减情节(组图)
2010影响世界的50人--詹姆斯.卡梅隆(第30位)
盘点《哈利波特》系列十大倒霉人物
神往《哈利.波特》魔幻的英伦外景地
Top10:有争议的同性恋(LGBT)电影
莱昂纳多未来几年的新片计划
对比照:长大后的好莱坞童星们
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |