16. The film, ____________ a true story, attracts people’s attention all over the world.
A. base on B. to base on C. based on D. basing on
17.Alexander tried to get his work _____________ in the medical circles.
A. to recognize B. recognizing C. recognize D. recognized
18. We won’t start the work until all the preparations _______________.
A. being made B. have been made C. will be made D. had been made
19. In order to find the missing child, villagers ______________ all they can over the past 5 hours.
A. have been doing B. had done C. do D. did
