. A nature reserve for white-flag dolphins was set up in 1992, _______ boats have been prohibited from sailing around since then.
He suggested the problem worth paying attention ______ at the meeting.
I fixed my eyes upon the newcomer, wondering whether I ________ him somewhere before.
一I’m sorry! I would have taken him to hospital if I had known he was seriously ill. 一But ______ .
The question that puzzled them is ____ they can get rid of the air pollution in the area.
It is reported that many a new house ____ at present in the disaster area in Gansu Province.