—Have you seen Jack recently?—No. He      for another company now.

Great changes ______ in my school in the past ten years.

Going on holiday not only __________you feel good while you’re there --- you reap the health benefits for months, new research shows.

—Did Tom live here?—Yes，but he________here now. 

—Is there any possible way to help them get rid of such a bad habit?—To tell the truth, it’s very hard. But we ________ on this problem, trying to improve the situation .