Work hard _____ you can succeed.

Tom is in low spirits today. He ______ again in the job interview.—What a pity! He has been greeted with bad luck these days.

I met Li Lei_____ hospital last Sunday. He was ill_____ hospital then.

Before you pay a visit to a place of interest, look in your local library a book about it.

Most disaster experts believe there is the potential______ things could get a lot worse.