『新东方在线托福口语』为托福考生准备了ETS托福TPO/Official 28 Task 4口语练习：<img src="/upload/ti/2427000-2428000/2427052/6ffd70318c084a1dbb1ae1611860d75d.jpg">
<br>&nbsp;&nbsp;原文题目答案解析，TPO/Official 28 Task 4口语原文范文音频翻译。

托福TPO/Official 28 Task 4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：来听地质学课上讲座的一部分。

Narrator: Listen to part of a lecture from a Geology class.

教授：所以当我们观察湖泊时，它们似乎是永久性的，我们假设它们会永远存在。

Professor: So when we look at lakes, they seem to be permanent, we assume they'll be around forever.

但事实上，湖泊并不是永久的，它们实际上可以消失。

But in fact, lakes aren't permanent, they can actually disappear.

有时它们通过自然过程消失，有时是因为人类活动。

Sometimes they disappear through natural processes and sometimes because of human activities.

首先，让我们看看湖泊自然消失的一种方式，

First, let's look at one way lakes can disappear naturally,

这是逐渐被有机沉积物填充的。

and that is by gradually getting filled in with organic sediment.

这经常发生在有很多植物生长的湖泊中。

This often happens with lakes that have lots of plants growing in them.

它们分解成一种泥状物质，落在湖底。

they break down into a muddy substance which falls to the bottom of the lake.

然后又被新的植物所取代，这些植物最终也会死亡并沉入湖底。

There then replaced by new plants which eventually also die and fall to the bottom.

这些年来，所有这些死去的植物材料都堆积在湖底。

And over the years, all this dead plant material builds up on the bottom of the lake.

随着它的积累，它开始填满整个湖，水的空间越来越小。

And as it builds up, it starts to fill up the lake and there is less and less room left for water.

最终，这个湖完全被填满并消失了。

And eventually the lake is completely filled in and disappears.

好吧，湖泊也会很快消失，有时是人类活动的结果。

OK. And lakes can also disappear, pretty rapidly sometimes, as a result of human activities.

例如，我们知道农民需要水来灌溉他们的庄稼。

For example, we know that farmers need water to irrigate their crops.

有时为了得到水，他们把水从附近的湖里抽出来。

And sometimes to get that water, they pump the water out of a nearby lake.

他们安装从湖到他们的农场的管道，他们把水从湖中抽水到他们的田地里。

They install pipes that run from the lake to their farms and they pump the water out of the lake and into their fields.

如果湖水不停地充满雨水，这样引水是可以的，

That's okay if the lake is continually being refilled with rainwater, or with water from streams that run into the lake.

或者是有小溪水不断流进湖中补充也可以。

or with water from streams that run into the lake.

但是，如果没有足够的雨水或溪水来替代农民从湖中取的水，

But if there isn't enough rainwater or stream water to replace the water the farmers take out of the lake,

<img src="/upload/ti/2427000-2428000/2427052/6ffd70318c084a1dbb1ae1611860d75d.jpg">
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<p>Using points and examples from the lecture, describe two ways that lakes can disappear.</p>