Fruit and vegetables are _________food.

The number of the red-crowned cranes will become ____ if we don’t take any action.

______ is obvious ______he has finished his work.

Why do you keep the windows open on such a cold day? —There are so many students here, so we want to keep the air nice and __.

What are you doing, Jack?—I’m looking for some information about the event ________ attracts all the people’s attention.