会员:密码:
注册会员忘记密码?我浏览过的资料
设为首页加入收藏夹加入QQ书签
首页每天学英语背单词新概念走遍美国音标词汇语法研究生大学高中初中小学少儿演讲有声圣经VOA商务

您所在的位置: 大耳朵首页 > 听力资料 > 在线视听资料 >...> 新东方 > 新东方英语现代文背诵篇章50 > 正文

站内搜索:

小提示:学单词背单词请到大耳朵免费在线背单词系统
trot/[trɔt]/v.&n.小跑,快步走
新东方英语现代文背诵篇章34
34 Raising Oysters

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.

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!
共有0人向本资料提供了听力原文,其中被采用了0篇,当前有0篇待审批,有0篇未被采用! 查看明细>>
如果您有更好的听力原文,欢迎提供给大耳朵,如果被采用,您将获得20到100金币的奖励!
  
已有1位对此听力感兴趣的网友发表了看法
非常好 很好 一般 不好 很差
* 如果因您不良评论或重复评论导致评论被删,您将会被扣掉一定数额的金币。
* 您必须遵守《全国人大常委会关于维护互联网安全的决定》及中华人民共和国其他有关法律法规。
* 承担一切因您的行为而直接或间接导致的民事或刑事法律责任。
* 您发表的文章仅代表个人观点,与大耳朵网站无关。
* 大耳朵评论管理人员有权保留或删除其管辖评论中的任意内容。
* 您在大耳朵网评论系统发表的作品,大耳朵网有权在网站内转载或引用。
* 参与本评论即表明您已经阅读并接受上述条款。
新东方英语现代文背诵篇章50
高瞻远瞩
放眼全球
推荐资源
最新论坛精华帖子更多>>
经典学习方法更多>>
听力资料目录导航
听力测试 英语词汇 英语口语 考试英语 品牌英语 大学教材 其他教材 商务英语 广播英语 儿童英语
历年中考听力
初中中考模拟
历年高考听力
高考听力模拟
历年四级听力
历年六级听力
四级听力模拟
小学  初中
高中  四级
六级  考研
托福  GRE
星火记忆单词
用Mp3背单词
刘毅词汇记忆
情景英语口语
4+1听力口语
出国实用会话
英语口语8000句
新东方900句
美语听力与发音
ABC到流利口语
口译考试
剑桥考试
中高考考试
大学四六级考试
研究生考试
公共英语考试
英语专业考试
新概念 六人行
赖世雄 许国璋
走遍美国 越狱
疯狂英语 沛沛
语法讲座 动感
大山英语 探索
千万别学英语
大学英语听力
大学英语精读
全新版 21世纪
新视野 实用综
大学体验 新编
成人自考 step
Listen this way
广州版小学英语
广州版初中英语
剑桥少儿英语
朗文3L看听学
Goforit新目标
高中英语课本
进阶听说教程
商务英语300句
VOA商务英语
商业英语视频
中级商务英语
初级剑桥证书
新编剑桥英语
剑桥英语精华版
2007年VOA慢速
VOA中级美语
美国习惯用语
VOA流行美语
澳广播英语讲座
在线大学课堂
VOA视频节目
宝宝ABC
棒棒英语
哈哈美语
LittleFox儿歌
英语儿童故事
380英语小故事
1035个英语单词
免责声明:本站只提供资源播放平台,如果站内部分资源侵犯您的权益,请您告知,站长会立即处理。
Copyright © 2003-2010 大耳朵英语  京ICP备10010568号

0.001211s