The air ______ different gases _____ together.

fluence of this book might not have been reaching so far,________for Mr William, who dared to publish it

My baby has a heart trouble—- Did the doctor find it difficult ______

The American economic crisis is hanging over the whole world now,but I still hope that we can _____ this as soon as possible.

It can’t be too worse.—Just _____. Things will turn out to bebetter so long as you don’t stop trying.