—The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job? —_______ my students have a try?
-- Have you seen ______pen? I left it here this morning -- Is it ______black one? I think I saw it somewhere
Great changes ______ in the past few years, and a lot of factories ________.
—What about going for a walk? —______.
______ with routine office tasks, she had no time to look after her children.
The audience ______ to see who would win the gold medal.