短语词组短语knock on the cage door 敲鸟笼的门;啄笼子的门;敲笼子的门a knock on the door 敲门声Loud knock on the door 大声敲门to knock on the door 打门Knock on the classroom door 敲教室的门knock on the neighbour 's door 敲 返回 knock on the door