介词填空 We are _____ a school trip and having a good time.
介词填空 We are _____ a school trip and having a good time.
介词填空 We are _____ a school trip and having a good time.
介词填空 We are _____ a school trip and having a good time.
be.on.a.trip.固定搭配
on,绝对的好伐
on
on理由go on a school trip理由后面用了现在分词啊那也是on就是这么搭配的