George, how can you prove the earth is round—I can’t, sir. ______, I never said it was.

It is reported that a man ________off an old lady in the street yesterday.[ ]

Tom fell in love with Dongying and he decided to find _______ job as a foreign teacher here.

With a lot of difficult problems________, the manager felt worried all the time.[ ]

In those days, our ______ concern was to provide people who were stopped by the snow storm withfood and health care. [ ]