以下是某校的校规，请根据内容按四个不同场所归类，并将其序号填入下面相应的横线上。每一横线只能填一个序号：

A. You must not draw on the blackboard. B. You must return the books in time. C. You must not step the grass. D. You must put back the books after you have read them. E. You must not talk to drivers when the bus is moving. F. You must clean the classroom every day. G. You must not jump the queue when you wait in line for the bus. H. You must put away the balls after you have used them.

请你按照以上校规，用英文为自己学校制订一条合理的校规：
小题1:_________________________________________________________________