Food supplies may ________ towards the end of the trip, so we can’t waste any food.
This sweater fits me, but I can’t afford to buy __________. I have to choose _________ which is cheap enough for me.
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.