课程咨询
托福培训

扫码免费领资料

托福全科备考资料

免费水平测试及规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

托福IBT必背经典文章:浮游生物

2015-06-05 11:11:43来源:网络

  【新东方托福IBT必背50篇经典文章:浮游生物这份资料可以帮助考生在托福网考备考过程中,提高托福口语水平,同时对提高托福写作水平和托福阅读都有很大帮助。托福IBT必背50篇经典文章,助你托福考试成功!

  新东方托福IBT必背50篇经典文章:浮游生物

  Plankton浮游生物

  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 sea’s 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 sea’s 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 devours more than one ton of krill daily.

  查看全部:新东方托福IBT必背50篇经典文章



托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料