I don’t think the campus is interesting, _____? — _____. I agree with you. [ ]

________ Mary ________ Jack is listening to the report carefully, because they are both interested in it very much.

He knew the problem was serious and promised to look into it ____ he reached office[ ]

It is uncertain ________ side effect the medicine will bring about, although about two thousandpatients have taken it.[ ]

What are you doing there—-Listen, Mum! I hearsomebody______upstairs.