Do you prefer _______

I’d like to invite you to a party tomorrow evening.– Thank you, but ______ I’ll be free I’m uncertain

Is Kate serious? —I _________. She never means it.

(2013·厦门第一次质量检查)You had better book rooms at the hotel in advance ________ you should find no room on your arrival

The question that puzzled them is ____ they can getrid of the air pollution in the area.