Mr. Smith was in trouble those days. He drove a car for Mr. Black, a rich businessman. He worked hard and the shopkeeper liked him. But he couldn’t work when he drank too much. And once he a
–I’m _____ to eat an elephant now! ---Oh, dear. But I don’t have ______ for you.A hungry enough ; many food B hungry enough; enough foodC enough hungry; enough food D enough hung
mgT，做功为零，重力冲量为
mgT.