1.The student must hand in their compositions before school is over.改为被动语态

问题描述:

1.The student must hand in their compositions before school is over.
改为被动语态

The students' compositions must be handed in before school is over

the compositions must be handed in before school is over(by the students)

The student's compositions must be handed in before school is over.

The students' compositions must be handed in before school is over.