听力文摘：闪电有助于肥沃土壤（在线收听）

Lightning Helps Fertilize The Soil

闪电有助于肥沃土壤

Our bodies need protein, and proteins contain nitrogen. The air we breathe has plenty of nitrogen to satisfy our needs.

人体需要蛋白质，蛋白质中含有氮元素。我们呼吸的空气中有许多可以满足我们需求的氮，

But—that nitrogen is not available to us directly from the air.

但我们无法直接从空气中汲取氮，

The only way we can get nitrogen is from the plants we eat, or from the animals we eat that eat the plants.

我们获得氮元素的唯一方法就是通过我们吃的植物或是以植物为食的动物中获得。

Here's The Problem:

问题出现了：

A nitrogenmolecule in the air consists of two atoms which are held together very tightly.

空气中的氮气分子是由两个连接紧密的氮原子组成，

In order for us to absorb nitrogen, the two atoms must be separated.

要吸收氮元素就必须将两个原子拆开，

But the two atoms are held together so tightly that our body chemistry does not have enough energy to process them.

但是人体内产生的化学能并不足以打破如此紧密的连接。

This is where lightning comes in. Obviously we don't have to be struck by lighting in order to satisfy our need for nitrogen!

这时候，闪电就有用武之地了。很显然的事，我们不需要为了满足对氮元素的需求而去遭电击。

However, in a thunderstorm there is enough electrical energy in lightning to separate the nitrogen atoms in the air.

但是，狂风暴雨中的闪电释放的能量足以拆散空气中的氮原子，

Once the atoms are separated they can fall to earth with rain water,

被打散的氮原子随着雨水落入泥土，

and combine with minerals in the soil to form nitrates, a type of fertilizer.

与泥土中的无机物相结合形成硝酸盐（可作为肥料）。

The nitrogen-containing nitrates in the soil are absorbed by the plants,

泥土里含氮的硝酸盐会被植物吸收，

and when we eat the plants or the animals which eat the plants, we get the nitrogen in a form which our bodies can use.

当我们吃到这些植物，或者吃到以这些植物为食的动物时，我们就能以身体可吸收的形式获得氮元素了。

So, in addition to providing a spectacular light show, and scaring us to death, lightning also helps fertilize the soil.

所以，闪电除了能展现电闪雷鸣的壮观景象和把我们吓坏来之外，还能有助于肥沃土壤。