---Can you tell me why you learn English so well ? ---It is very simple. _______ you work, ______ grades you will get.

Air pollution has become__________ than ever before. We must do something to stop it.

In my opinion, soccer is _____________ sport in the world.

. Which do you think tastes _______, Millie, the chicken or the fish?

----Which is _______ to understand, this book or that book?---- I think both of them are quite easy.