—The cars give off a great deal of waste gas into streets. —Yes. But I'm sure something will be done to __________ air pollution.
In my opinion, everyone has periods in their lives _______ everything seems very hard.
Tom _______ the TV set for $500,which was much cheaper than he had expected.
Henry’s birthday is on _______ Saturday next month,but I don’t remember _______ date.
______around the university, we then were taken to a building, ______ many scientists worked.
It’s a pity that you ______ leave so soon. Your uncle will be home in 10 minutes and he misses you so much.