1. A lot of things must be done to clean this river. 

2. That course hasn't been taught this semester.

3. My house isn't being painted because it's raining.

4. This paper is read by millions of people everyday. 

5. Has the date of the meeting been changed?

6. I was taken to school by my father everyday when I was small.

7. Money is usually changed at the bank.

8. My money was stolen from my purse this morning.

9. That problem was not referred to at the last meeting.

10. This kind of work has never been done by Maria before.

1. This mathematical problem could not be solved by anyone.

2. He is believed to pass the final exam.

3. She was so old that she can't carry that heavy case.

4. Seldom does he keep his promise.

5. Never have I traveled  by plane in my life.

6. Jack is too young to see horror films.

7. He was seen to have left the office yesterday.

8. Because it was raining, she came late.

9. They had the leak repaired this morning.

10. Alice advised me not to lend them any more money.

11. She made the decision to help him with some money.

12. We have to pay attention to the teacher's explanation.

13. It took him 2 hours to do the mathematical exercises.

14. It was too late for anything to be done.

15. Mary paid us a visit three days ago.