把下列主动语态的句子转换成被动语态的形式
问题描述：
把下列主动语态的句子转换成被动语态的形式
1.They will send you a bill at the end of the month.
2.Students must clean their classroom everyday.
3.You can't use a dictionary in the exam.
答
1.A bill will be sent to you by them at the end of the month.
2.Classroom must be cleaned by students everyday.
3.Dictionary can't be used by you in the exam.