AIDS is said________the biggest challenge to both men and women in that area over the past few years.
.He _____have solved all his probems; otherwise, he wouldn’t be so relaxed.
.Well, if watching TV or seeing a film doesn’t______ to you, how about going hiking, instead?
—Would you mind giving me and my classmates a gift to school? —___
.Was it ______ Expo 2010 that made Shanghai the focus of the world then?
—What was his performance like? —Oh, it couldn’t have been___.