Things you can do at school和Things you can't do at school越多越

can do:We can play sports .We must listen to the teacher carefully .We may listen to music We should do exercises.
can not:We can't speak when the teacher gives a lesson.
We can't eat anything in class .
we can't fight with others.
We can't sleep when the teacher gives a lesson.

can do: playing chating singing dancing
can not: smoking fighting crying sleeping