Plankton 浮游生物

如浏览器阻止,请点“保留”,即可自动下载.
推荐度:
点击下载文档

文档为doc格式

文档打印预览下载帮助

Plankton 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.

编辑:Liuxuepaper.Com

作文地带知识拓展:

    英语作文

  • 英语作文,是指用英语针对某一内容写出一篇文章,是英语考试最常见的一种题目类型,英语作文要求阅读、写作能力比较高,也是考生最容易失分的题型。英文书写应符合书写规范,英文字母要写清楚、写整齐、写美观,字母的大小和字母之间的距离要匀称。书写应做到字形秀丽漂亮,通篇匀称和谐。

Plankton 浮游生物

如浏览器阻止,请点“保留”,即可自动下载.
推荐度:
点击下载文档

文档为doc格式