The world economy has improved _____ since the end of last year, but major problems and challenges are not fully solved.
28. I'm afraid we'll have to work extra hours for there are still some problems ________.
27. Since I don’t like many vegetables, can I eat fruits every day instead____ the nutrients I need?
26. How long do you think ________ the computer company brings out a new product?
25.He left for lunch________ the clock_________ twelve.
24. The boy the teachers considered _____ was caught ______ in the exam, which surprised us very much.