hand in和hand up的区别

hand in:上交;递交

1.As for cheating, teachers can ask students to hand in their iPads when they take exams. 至于作弊，老师可以要求学生考试时上交他们的ipad。

hand up: 举手

1.And I kept my hand up because I did the reading and knew the answer. 我一直把手举着，因为我温习过知道答案。