『新东方在线托福口语』为托福考生准备了ETS托福TPO/Official 48 Task 3口语练习：Optimal Foraging &nbsp;
Food provides anima原文题目答案解析，TPO/Official 48 Task 3口语原文范文音频翻译。

托福TPO/Official 48 Task 3口语原文独立/综合口语题目答案解析-范文音频翻译-新东方托福官方网校手机版

旁白：现在来听生物学讲座上的一部分。

Narrator: Now listen to part of a lecture from a Biology class.

教授：好的，我有一个很好的例子。

Professor: All right. So I've got a good example of this.

有一种鸟，一种生活在水面附近的乌鸦。

There's a bird, a species of crow that lives near the water.

它以一种有坚硬外壳的贝类为食。

And it feeds on a type of a shellfish that has a hard outer shell.

这只鸟必须打开它坚硬的外壳。

the bird has to crack open its hard shell.

它所做的是从空中俯冲到浅水中，

what it does is it dives down out of the air into shallow water,

then carries the shellfish up in the air.

然后它会松开贝壳，让它落在下面的岩石上。

It then drops the shellfish, lets it fall onto the rocks below.

its shell cracks and splits open and the bird can eat it.

这种乌鸦不只是俯冲下来，抓住它看到的第一个贝类，然后飞到任何高度，让贝壳掉落。

this crow doesn't just swoop down, grab the first shellfish it sees and then fly up to any height and let it fall.

首先，它谨慎地选择最大的贝壳。

First, it carefully selects only the biggest shellfish.

这意味着它将为自己的努力争取到最饱腹的一餐。

That means it's going to get the biggest possible meal for its efforts.

它把贝壳带到一个特定的高度，

it carries the shellfish up to a specific height,

大约5米，然后从那里松开贝壳。

about five meters, and drops it from there.

如果鸟从较低的高度扔下贝壳，

If the bird dropped the shellfish from a lower height,

为了打破外壳，它必须把它捡起来扔了很多次。

it would have to pick it up and drop it too many times in order to break the shell.

如果这只鸟把贝壳带到更高的高度，

if the bird carried the shellfish up to a higher altitude,

an altitude higher than is necessary to crack the shell,

所以这种鸟只运用正好的力量，

So this bird expands just the right amount of energy.

that it needs to obtain just the right kind of food.

Optimal Foraging &nbsp;
Food provides animals with the energy they need to survive. However, animals also lose energy in the process of obtaining, or foraging, for food. Therefore, in order to conserve energy, many animals behave in ways that minimize the energy they expend in the foraging process while at the same time maximizing their nutritional benefits. This energy-efficient approach to obtaining food is known as optimal foraging. The practice of optimal foraging allows animals to expend the least possible amount of energy while at the same time obtaining prey with high food value that will provide them with necessary nutrients.
 
<img src="/upload/ti/2340000-2341000/2340616/2b593be439bb4ad18edbbcc21b795ed5.png">
 &nbsp;&nbsp;
 Using the example from the lecture, explain the concept of optimal foraging.
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