Wearesupposedtolisten________theteacherinclass.A.atB.onC.toD.in

问题补充：

We are supposed to listen ________ the teacher in class.A.atB.onC.toD.in

答案：

C解析listen“听”是个不及物动词，“听……（讲，说）”时，应在其后加介词to。