It keeps them high in the sky.

它使它们在天空中保持高高的。

It has no colour or shape.

它没有颜色和形状。

It has no smell or taste.

它没有气味和味道。

We cannot see it, but we can feel it.

我们不能看见它，但是我们可以感觉到它。

It is everywhere.

它到处都是。

It is important to all people.

它对所有人都很重要。

It is also important to animals and plants.

它对动物和植物也很重要。

We all need it to keep us alive.

我们都需要它使我们活着。

Look at the kite and the balloon.

看风筝和气球。

Look at the plane and the bird.

看飞机和鸟。

They all need it too.

它们也都需要它。

It keeps them high in the sky.

它使它们在天空中保持高高的。

What is it?

它是什么？