You must not talk ( )your phone when you are having a class填空,并说明理由

You must not talk ( )your phone when you are having a class填空,并说明理由
You must not talk ( )your phone when you are having a class
填空,并说明理由

You must not talk ( )your phone when you are having a class填空,并说明理由
on
talk on phone是固定搭配

on
talk on the phone 指打电话，是固定搭配
在电话上打，因此用on

（）应该是on吧
就是上课的时候禁止打电话

ON
只是一个考查短语的句子，意思是在喝水的时候不要讲电话

填with 译过来就是“你不能在上课时用手机交谈” 不难想 这里填介词 所以只能用with 用手机啦

on
固定搭配 标示打电话