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
牛津版一年级英语上册unit5 Fruit教案(2)
一年级英语教案Module1 unit6 Mid-Autumn Festival
一年级英语上册教案Unit1 My classroom第一课时
一年级英语Module1 unit6 Mid-Autumn Festival教案
新起点小学一年级英语下册Unit11 Toys教案
一年级英语上册教案Unit1 My classroom第一课时教案
一年级英语下册Unit2 Small animals第三课时教案
上海牛津版一年级英语下册Unit2 Small animals教案
苏教版牛津小学一年级英语教案Unit1 What`s your name
新起点小学一年级英语教案Unit7 Fruit
沪教版小学英语一年级下册教案unit1课时3
一年级英语上册Unit1 My classroom第三课时教案
牛津版一年级英语上册教案Unit4 My bag第一课时
上海牛津版一年级英语下册教案Unit9 Revision(3)
上海牛津版一年级英语下册Unit9 Revision第一课时教案
上海牛津版一年级英语Unit7 My family教案
上海版牛津一年级英语教案Unit8 Playtime(总五课时)
沪教牛津版小学英语一年级上册 unit9 教案
沪教版小学英语一年级下册教案unit1课时2
上海牛津版一年级英语下册Unit9 Revision第二课时教案
沪教版小学英语一年级下册教案unit1课时4
沪教版小学英语一年级下册教案unit1单元分析
上海牛津版一年级英语下册Unit2 Small animals第五课时教案
苏教版小学一年级英语下册Unit5 On the road教案
沪教版小学英语一年级下册教案unit1课时5
沪教牛津版小学英语一年级上册 Unit 8 教案
沪教牛津版一年级英语上册教案Unit1 My classroom第二课时
一年级英语上册教案 Unit 1 第二课时
上海牛津版一年级英语下册Unit3 Colours教案(1)
沪教牛津版小学英语一年级上册 Unit3 period2教案
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |