为了帮助大家熟悉历年托福听力，沈阳新东方网为大家带来托福听力题目:鳗鱼的研究一文，希望对大家的备考有所帮助!更多托福考试相关资讯，请随时关注沈阳新东方网!

　　生物：对eel这种鱼的migration的研究，发现它们白天在水面晚上潜到水里来prevent mature。

　　一种鳗鱼(eel)，会从欧洲到一个某海。这个海是唯一一个被海流包围的海，研究者从来没发现过确切的路线.一个新研究在鳗鱼身上放了标记，但在它们到某海之前就失效，有两个发现：

　　a.它们不走最短的路，而是跟着洋流走最efficient的路线

　　b.鳗鱼白天在海上部，晚上会游到下面冷的海水，是因为他们出发前还没有足够成熟，通过低温降低代谢效率减缓生长。

　　1. What is the purpose of the lecture?

　　To illustrate the difficulty of determining whether a certain species needs protection under the Endangered Species Act

　　2. Why do some experts think the American eel should not be considered endangered?

　　They can survive a wide range of environmental conditions.

　　3. What did several government agencies conclude about the size of the American eel population based on their survey?

　　It will increase and decrease periodically.

　　4. What problem does the professor emphasize about the population surveys of the American eel?

　　They have not provided an adequate estimate of the overall population.

　　5. Why does the professor mention that the American eel is a catadromous species?

　　To help explain the difficulty in determining the true size of the American eel population

　　6. What does the professor imply about the physical transformation of the American eel when she says this:

　　“Then during the course of their lives, they go through a series of physical transformations which are interesting in themselves. I think there are something about that in one of your readings.”

　　They are not a subject she will discuss in her lecture.