电脑桌面
添加小米粒文库到电脑桌面
安装后可以在桌面快捷访问

托福考试阅读冲刺

托福考试阅读冲刺_第1页
1/20
托福考试阅读冲刺_第2页
2/20
托福考试阅读冲刺_第3页
3/20
第 1 页精品文档---下载后可任意编辑托福考试阅读冲刺 为了让大家更好的预备托福考试,我给大家整理了托福考试阅读冲刺,下面我就和大家共享,来观赏一下吧。 托福考试阅读冲刺 1 It is estimated that over 99 percent of all species that ever existed have become extinct. What causes extinction? When a species is no longer adapted to a changed environment, it may perish. The exact causes of a species death vary from situation to situation. Rapid ecological change may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food resources may be affected by environmental changes, which will then cause problems for a species requiring these resources. Other species may become better adapted to an environment, resulting in competition and, ultimately, in the death of a species. The fossil record reveals that extinction has occurred throughout 第 2 页精品文档---下载后可任意编辑the history of Earth. Recent analyses have also revealed that on some occasions many species became extinct at the same time — a mass extinction. One of the best-known examples of mass extinction occurred 65 million years ago with the demise of dinosaurs and many other forms of life. Perhaps the largest mass extinction was the one that occurred 225 million years ago, when approximately 95 percent of all species died, mass extinctions can be caused by a relatively rapid change in the environment and can be worsened by the close interrelationship of many species. If, for example, something were to happen to destroy much of the plankton in the oceans, then the oxygen content of Earth would drop, affection even organisms not living in the oceans. Such a change would probably lead to a mass ext...

1、当您付费下载文档后,您只拥有了使用权限,并不意味着购买了版权,文档只能用于自身使用,不得用于其他商业用途(如 [转卖]进行直接盈利或[编辑后售卖]进行间接盈利)。
2、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。
3、如文档内容存在违规,或者侵犯商业秘密、侵犯著作权等,请点击“违规举报”。

碎片内容

托福考试阅读冲刺

确认删除?
VIP
微信客服
  • 扫码咨询
会员Q群
  • 会员专属群点击这里加入QQ群
客服邮箱
回到顶部