Experts have been warning___of the health risks caused by passive smoking.
Hearing the old man’s report, the officer _______ from his seat and said something must be done to ________ people’s living standards.
Instead of ________sights, Edison would spend the time ________in the public library.
I had not listened to my mother’s advice on taking an umbrella. Later that afternoon, I was nearly ________ the rain.
It was on a cold winter evening_______ his father left home and was never back.
These books are for students ____ mother language is not English.