knock at the door 和 knock on the door有什么区别吗

knock at the door 和 knock on the door有什么区别吗 knock the door和knock on the door都对吧?有区别 knock at the door knock at the door造句 关于knock at the door. knock at a door和knock on a door的区别是什么 敲门英语可以说成 knock at on the door 因为书上写 knock at (on) the door o Listen:Someone ______(knock) at the door. knock on the door 同义句 Who is_______(knock)on the door? there was a knock on the door. There came a knock on the door