根据句子意思，填入合适的介词。小题1:You should listen __________ the teacher

根据句子意思，填入合适的介词。
小题1:You should listen __________ the teacher in class.
小题2:Are you ready __________ the class?
小题3:There are two beautiful pictures __________ the wall.
小题4:Happy Birthday! This is the present _________ you.
小题5:We are having a sports meeting __________ the playground now.