1. i an appointment to see the optician.2. after he his homework, he found he a mistake.3. this drug can miracles for people with back problems.4. they a lot of changes in the town centre recently.5. you the right thing by telling the police.6. he an archaeological discovery.7. after being ill for two weeks, he is now an excellent recovery.8. she a lot of research in the field of medicine.9. i an arrangement to meet him at the cinema yesterday.10. it is important that you exercise in order to keep fit.11. all that smoking you harm.12. he an excuse and left 

1. I made an appointment to see the optician.

2. After he had done his homework, he found he had made a mistake.

3. This drug can do miracles for people with back problems.

4. They have made a lot of changes in the town centre recently.

5. You did the right thing by telling the police.

6. He has made an archaeological discovery.

7. After being ill for two weeks, he is now making an excellent recovery.

8. She has done a lot of research in the field of medicine.

9. I made an arrangement to meet him at the cinema yesterday.

10. It is important that you do exercise in order to keep fit.

11. All that smoking is doing you harm.

12. He made an excuse and left.