They are still very cautious about ______ side effect the new medicine will bring about, although the experts have tried it on about 2,000 patients.
This is the second time that the top 10 list of popular novels _____ published by this magazine.
---Do you still smoke heavily? --- No. In fact, it is two years since I ____. A. have stopped smoking B. smoked D. began to smoke D. started to smoke
--- Is your new team-mate a good guy? --- Yes. He is kind, skillful, hard-working and intelligent; ____, I can’t speak too highly of him.
Having never met with such a _____ problem, he felt _____ and didn’t know how to solve it.
Officials believe that more than one person _____ for the big fire.