The building ________ will be used as ournew library.

The air is badly ________.And there’s more water _______ in the world.

It’s an ________well (井). Stay away from it.

Excuse me. Is this the way to the Summer Palace?—Sorry, I am not sure. But it ________be.[ ]

______ is believed that morning exercise isone of the best ways for a person to keep fit.