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
幼儿启蒙英语儿歌推荐:拇指在哪里
论坛热帖:我教3岁女儿学习英语的经验
幼儿启蒙英语儿歌推荐:老麦克唐纳
学前英语家长该注意九大问题
英语启蒙:先练发音、慢练胆子
幼儿启蒙英语儿歌推荐:如果幸福
幼儿启蒙英语儿歌推荐
学前英语:切勿让孩子累趴在起跑线上
幼儿启蒙英语儿歌推荐:爱之歌
学前英语学习 兴趣最重要
幼儿启蒙英语儿歌推荐:脑袋和肩膀
幼儿启蒙英语儿歌推荐:三只小猴
学前英语学习需要注意的几点
幼儿启蒙英语儿歌推荐:走
幼儿启蒙英语儿歌推荐:泰迪熊
幼儿启蒙英语儿歌推荐:咯咯嘎嘎
幼儿启蒙英语儿歌推荐:拍手
学前儿童英语学习注意事项
专家指导:学习英语应从兴趣入手
学前英语在线学习网站推荐
学前英语教育的现状分析
如何教学前孩子学英语
幼儿启蒙英语儿歌推荐:小星星
幼儿启蒙英语儿歌推荐:五只小鸟
如何给孩子“进补”学习英语的乐趣?
专家支招幼升小学生开学良方
幼儿启蒙英语儿歌推荐:我是一只小茶壶
幼儿启蒙英语儿歌推荐:桑树林
幼儿启蒙英语儿歌推荐:打雷
幼儿启蒙英语儿歌推荐:系鞋带
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |