The Sino-U.S. relations, although they have experienced twists and turns in the past, ______ have moved forward.
If you had told me in advance, I ___ him at the airport.
I wish I ___ able to tell him all about it last night.
—How about Christmas evening party? —I should say it was success.
People who are infected with HIV are often looked down upon becausesocial _____ against the diseaseruns so deep.
In human, there is a possibility of____ such as fever and headachesif there is exposure to the virus.