6、Every means _______ been tried to solve the difficult problem.

27. Tom( )more than twenty pounds on the novel.

26. I fell and hurt myself while I()basketball yesterday

25. The boy is not happy at the new school. He has()friends there.

24. He is not seriously ill, only a()headache.

23. I’d like the teacher()classes are very interesting and creative..

22. I didn’t expect you to turn()at the meeting yesterday.

21. We worked hard and completed the task().

20. Once environmental damage(), it takes many years for the system to recover.

19. The red flower goes from one to()in the class

18. Two days is not enough for him to finish the work. He needs()day.