The advertising firm usually collects ________ possible about the product.
As the quality of the city’s air continues to give rise to ________, the residents are encouraged to drive cars less often.
Not until the bus disappeared in the distance ________ her school bag was gone.
When I was a little girl, I ________ with my uncle for several years.
We students should treasure the short senior school’s study life of three years. Once ________, the opportunity can’t get back.
She suggested the problem worth paying attention ________ at the meeting.