It was in the school ____ he had studied ____ he began the important experiment.

The contest is so easy, but you fail to pass it.— I’m sorry it ______ be this way. [ ]

Playing balls together is a kind of activity_____ every playerneeds to be well-cooperated together.

It is uncertain ___ side effects these weight-loss drugs will bring about, although hundreds of thousands of patients have taken it

I thought you ____ like something to read , so I have brought you some books .