The population has ________（降低）to 500 in our village in the past three years.
The guests made a number of ______ (评论) about the service of the hotel.
I _____ (感激) him very much at the meeting because he had offered me some suggestions on how to improve my oral English.
I feel ____________（背叛）by my friend Hannah, because she hasn’t kept her promise that she will not tell others about my failure in math.
It is everybody’s ____________（责任）to make our country stronger.
Time passes quickly when you are a_____________ in reading a good book.
He p______ to be reading when his mother came in.
Mr. Qian Liwei is a business development c____________, to whom we can turn if we have any questions.
Pollution does harm to our health, so we should take m__________to stop it.
Safety taken into consideration, Mary’s parents hesitated to give p_____ for her driving alone when she was in senior high school.