—I drove to Zhuhai for the air show last week.—Is that ________ you had a few days off?
We are faced with the problem _________ we should do with so much pollution.
The naughty boy spends most of his time playing computer games ______ his lessons.
——Thank you for showing me the way!——____________. I live nearby, so I am familiar with this area.
________ by his brothers, he could continue his study in the university.
Professor James will give us a lecture on the Western Culture, but when and where _________ yet.