A. You must not draw on the blackboard.
B. You must return the books in time.
C. You must not step on 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.
Classroom ___________
Library _______________
School bus ________  
Playground _______________
仿照以上校规， 用英文为自己的学校制订一条合理的校规：
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