【简答题】We must keep our classroom cleanly.
【单选题】We must keep our school clean.
【单选题】We must keep up with the development of the worlds leading enterprises ______we can keep pace with the changing of the international situations.
【单选题】We must keep on learning if we want to keep up with the of the changing times.
【简答题】柴油机燃料供给系主要有几部分组成?各部分的功用是什么?
【单选题】We must keep our classroom().