we must study hard. we musn't waste our time. we must follow the rules of the school. we mustn't break them. we must listen to the teacher carefully.we mustn't talk with each other at class.追问
i must contribute myself to study. i mustn't smoke in the classroom. i must listen to the teacher carefully. i mustn't talk with student in class. i must take part in the acitivities at school. i mustn't sleep in the classroom.
第2个回答 2011-10-30
we must study hard. we musn't waste our time. we must follow the rules of the school. we mustn't break them. we must listen to the teacher carefully.we mustn't talk with each other at class.