“WeChat” really makes a great _____ to our life. More and more people use it now.

______ do you study for tests —I study_____listening to tapes.

With his work completed, the businessman stepped back to his seat, feeling pleased_____ he was a man of action.

I predict there will be fewer ____ in the future.

ce, too，the Red Cross is expected to send help _____there is human suffering.