所在位置: 查字典英语网 >留学英语 > GRE > GRE写作 > GRE写作范文——Plankton

GRE写作范文——Plankton

发布时间:2016-03-01  编辑:查字典英语网小编

  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 effect 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 plankton-burgers 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 shrimp-like creature called krill. Growing to two or three inches long, krill provides the major food for the great blue whale, the largest animal to ever inhabit the Earth. Realizing that this whale may grow to 100 feet and weigh 150 tons at maturity, it is not surprising that each one.

  

查看全部
推荐文章
猜你喜欢
附近的人在看
推荐阅读
拓展阅读
大家都在看

分类
  • 年级
  • 类别
  • 版本
  • 上下册
年级
不限
类别
英语教案
英语课件
英语试题
不限
版本
不限
上下册
上册
下册
不限