Why did you buy a radio?— English.A.Learn B.Learning C.To learn
There must be a boy ________ basketball outside the door. I hear him crying.
Have you done ____ to improve the environment ?
—Who helped Betty tidy up the bedroom just now?—________. She cleaned it all by herself.
The workers in the Huashan Mountains have to ______rubbish to keep the mountains clean.
— Whose shoes are these?— They ____ be Mike’s. They are much too large for him.