you mustn't be late for school.you can't ( )in class.you can

这个题答案不唯一只能让你参考下
you mustn't be late for school.you can't ( eat )in class.you can't ( smoke )in class.you must( listen carefully )in class.you should( put up your hand )when you want to answer yhe questions.if you want to go to the library,you should ( finish your homework first ) first .and you should( clean the classroom ).
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再问： 我想知道这句答案，你能不能换一个？if you want to go to the library,you should ( )the first .and you should( ).
再答： you should ( work\study )the first .and you should( finish your homework ).