大学新概念英语阅读（二）
【篇一】
Raising Oysters
In the past oysters were raid in much the same way as dirt farmers raid tomatoes- by transplanting them. First, farmers lected the oyster bed, cleared the bottom of old shells and other debris, then scattered clean shells about. Next, they ”planted” fertilized oyster eggs, which within two or three weeks hatched into larvae. The larvae drifted until they attached themlves to the clean shells on the bottom. There they remained and in time grew into baby oysters called ed or spat. The spat grew larger by drawing in awater from which they derived microscopic particles of food. Before long, farmers gathered the baby oysters, transplanted them into other waters to speed up their growth, then transplanted them once more into another body of water to fatten them up.
Until recently the supply of wild oysters and tho crudely farmed were more than enough t
o satisfy people’s needs. But today the delectable afood is no longer available in abundance. The problem has become so rious that some oyster beds have vanished entirely.
Fortunately, as far back as the early 1900’s marine biologists realized that if new measures were not taken, oysters would become extinct or at best a luxury food. So they t up well-equipped hatcheries and went to work. But they did not have the proper equipment or the skill to handle the eggs. They did not know when, what, and how to feed the larvae. And they knew little about the predators that attack and eat baby oysters by the millions. They failed, but they doggedly kept at it. Finally, in the 1940’s a significant breakthrough was made.
射雕英雄传歌曲The marine biologists discovered that by raising the temperature of the water, they could induce oysters to spawn not only in the summer but also in the fall, winter, and spring. Later they developed a technique for feeding the larvae and rearing them to spat. Going still further, they succeeded in breeding new strains that were resistant to dias, grew
faster and larger, and flourished in water of different salinities and temperatures. In addition, the cultivated oysters tasted better!
饲养牡蛎
过去人们饲养牡蛎的方式很大水准上类似于田地里的农夫种植蕃茄——通过移植来饲养它们。首先，农夫选好牡蛎苗床，清除底部的旧壳和其它杂物，然后四处撒播干净的壳。接着，他们“栽种”已受精的牡蛎卵。这些卵在2-3周内会孵化成幼贝。幼贝一直漂流直到粘在苗床底部干净的壳上为止。它们会呆在那儿并逐渐长成小牡蛎。我们称之为种子或贝苗。贝苗吸进海水中的微小生物作为食物从而越长越大。不久之后，农夫将这些小牡蛎收集起来，把它们移种进其他的水域加快其生长，然后再次将它们移种进另外的水域以使其肥壮起来。
直到最近，野生的以及人工饲养的牡蛎完全能够满足人们的需要。但是今天这种可口的海味已不再大量存有。这个问题已经变得如此严重以至于一些牡蛎苗床已完全消失。
幸运的是，早在20世纪初期海洋生物学家们就意识到如果不采取新的措施，牡蛎将会灭绝
崖山或至少会变为一种奢侈的食品。所以他们建造了装备良好的孵卵场所并开始工作。但是他们尚没有适当的装置或技术来处理牡蛎卵。他们不知道何时、用什么以及如何喂养幼贝。他们对捕食数百万幼小牡蛎的动物天敌也所知无几。他们失败了，但他们顽强地坚持了下来。终于，在20世纪40年代，一个重要的突破性的进展产生了。
海洋生物学家发现，升高水温能够诱导牡蛎不但在夏季也在秋季、冬季和春季里产卵。后来他们发展了一项技术来喂养幼贝至其长成贝苗。他们进一步成功地培养出了新的品种，能够抵抗疾病、长得更快、更大并且在不同的盐度和温度的水中都能茁壮生长。此外，这些培殖出的牡蛎口感更佳！
海作文【篇三】
一级士官Plankton
Scattered through the as of the world are billions of tons of small plants and animals called plankton. Most of the plants and animals are too small for the human eye to e. They drift about lazily with the currents, providing a basic food for many larger animals.
今天故事汇
供货价Plankton has been described as the equivalent of the grass 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 grass. One scientist has estimated that while grass of the world produce about 49 billion tons of valuable carbohydrates each year, the a’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 grass on land. Now marine scientists have at last begun to study this possibility, especially as the a’s resources loom even more important as a means of feeding an expanding world population.
No one yet has riously 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.
司马骏
One type of plankton that ems 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 t
鼠和蛇合不合
he 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.
