Take a guess,what is it ?(猜一猜,它是

What Is It?

You cannot see it,

You cannot taste it,

You cannot smell it,

And,

You can not live without it,

What is it?

IT IS AIR!

它是什么?

你看不见它，

尝不到它，

闻不到它，

而且，

没有它你不能生存，

它是什么?

它是空气。