21页7.Listen ,there is a knock ------the door .It must be Tom

21页7.Listen ,there is a knock ------the door .It must be Tom listen there is a knock at the door 改为同义句 there is a knock at the door.it is the second time that some A knock on the door!Who --it be? 可以说there is a knock at the door吗 Listen!There's someone_____(knock)at the door. there was a knock on the door. There came a knock on the door Listen!there`s a k______ at the door .who is it ' —There is a knock at the door.—---------------?A.who is that There was a knock at the door.It was the second time someone Suddenly there was a l___ knock on the door.It gave me such