The teacher as well as the students who _____ fond of football, _____ playing together.

You may have no idea _____ you will be doing ten years from now.

Walking up and down the stairs is a goodkind of exercise to stay _____.

Steve gave a look and said he had no idea what I was talking about.

Why did you go to the wrong class,Mr Wang " "Well, I forget _______ I was supposedto go to"