——Mom, my little sister is crying all the time.——Mary, be ________! She feels unwell.You should take good care of her.
—Is Mr. Smith over there? —It ________ be him. He has gone to Beijing on business.
-was the car invented? --It was invented in 1983.
I enjoy playing computer games, but I can't spend too much time ________ that.
________ is bad for your eyes ________ TV too much.
She is ________ poor ________ buy that nice dress.