I knocked down the cup.或I knocked over the cup.参考：请不要把那些罐子碰倒.Please don’t knock down all those cans.瓶子不可能自己倒下来,一定是有人碰了它.The bottle couldn't have fallen down of itself....
I knocked down the cup.或I knocked over the cup.参考：请不要把那些罐子碰倒.Please don’t knock down all those cans.瓶子不可能自己倒下来,一定是有人碰了它.The bottle couldn't have fallen down of itself....