What's the mean of exchange student?

What's the mean of exchange student? what's the mean of this word? What's the mean of ChinaJoy? what's the mean of right? What's the mean What's the mean of "What is it? what's the mean of ______It’s unfair? exchange student前加不加the What's the _______(mean)of the world? What's the _______(mean) of the world Tiger is a kind of the zoo? what's mean What's mean of the life?这是什么意思啊