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.
参考答案:
DBCBD
里约地铁耍体操“花样爷爷”走红
美游泳冠军里约被抢剧情大反转?
你要升职前的五个前兆
2岁萝莉和救命恩人警察来了个约会
网友两句话写出鬼故事 你敢看吗?
研究显示 口腔细菌竟可引发肠道癌
6个旅行时容易犯的健康错误
比尔克林顿呼吁选民支持希拉里
研究显示 性行为前吃阿司匹林有助生男孩
约翰尼•德普离婚 支付七百万赡养费
善待他人,你也将成为更好的自己
希拉里获提名 百位名人联名反对特朗普入主白宫
中国司机发明了“汽车裙”来防范老鼠
奥运特供:里约旅游小贴士
中国首次跻身世界创新25强
李开复:15年内,全球半数工作将被人工智能取代
女游客野生动物园下车被老虎袭击
《哈利波特》新书,你看过了吗?
五种方法保持关节健康
离婚房子怎么分?可拆分式漂浮屋让分手更省心
10个值得一去的城市
里约奥运会 英国为何奖牌大丰收
女子4X100美国重跑淘汰中国抗议无效
多国奥运服装遭吐槽 伊朗队服似“橡皮擦”
为何政坛女强人青睐短发波波头?
一起去全球10大水上乐园消暑吧
各国人民最爱的美女标准身材:你猜中国啥样
老当益壮!拼搏在奥运赛场的老将们
奥运在即 祈祷场馆如期完工吧
两万封邮件揭秘希拉里竞选黑幕 美国上演现实版《纸牌屋》
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |