新东方四六级写作考试背诵范文精选（34）

2021-10-11 19:25:16 · 作者：编辑部

新东方英语四六级作文栏目：为您提供2021年12月大学英语四级作文范文、英语四级作文模板万能句型、英语四级作文题目、英语四级作文常用句型、英语四级作文万能句子等相关信息供大家参考学习。

·应急小贴士：四六级写作词汇量不足怎么办
·09年6月四六级考前必看范文
·六级作文高分技巧：精彩你的“强调”
·免费试听新东方在线四六级名师辅导课程

34 Raising Oysters

·2009年6月四六级考前必看范文

In the oysters were raised in much the same way as dirt farmers raised tomatoes- by transplanting them. First, farmers selected 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 themselves to the clean shells on the bottom. There they remained and in time grew into baby oysters called seed or spat. The spat grew larger by drawing in seawater from which they derived microscopic particles of food. Before long, farmers gathered the baby oysters, transplanted them once more into another body of water to fatten them up.

·四六级考试学习资料汇总第1辑
·四六级考试学习资料汇总第2辑
·四六级考试学习资料汇总第3辑

Until recently the supply of wild oysters and those crudely farmed were more than enough to satisfy people’s needs. But today the delectable seafood is no longer available in abundance. The problem has become so serious 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 set 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.

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 diseases, grew faster and larger, and flourished in water of different salinities and temperatures. In addition, the cultivated oysters tasted better!

相关阅读：
·女生包揽“四级明星寝室” 学英语有性别差异？
·校内书店跨校代报四六级校方申明成绩无效
·部分省市高校四六级考试报名截止严禁跨省跨校报考

【本文为找大学网转载，文章版权归原作者及原出处所有。文章系作者个人观点，不代表大学生在线立场，转载请联系原作者及原出处获得授权。有任何疑问都请联系（kf@zhaodaxue.cn）】