=>
4/
1. had commuted
2. had suffered
3. was
4. had mushroomed
5. hadn't built
6. had cooperated
7. had people done
8. had tried
9. had evacuated
10. had always wanted
5/
1. It is hard for Jim to do this task.
2. It is not easy for me to pass the test.
3. It is challenging for you to change your job now.
4. Mary is always afraid to try anything new.
5. Are you confident to win the competition?
6. My mother is pleased to see me at home now.
7. I am sorry to hear that you had an accident last week.
8. I am glad that you come to my party.
9. It is not surprising that Peter is the best student in his class.
10. I am convinced that Peter is right.
6/
1. sure -> am sure
2. presenting -> present
3. that -> for
4. winning -> to win
5. hearing -> to hear
6. to be -> is
7. astonished -> was astonished
8. pass -> to pass
9. be -> x
10. don't -> aren't
