1. The world is changing. Things never stay the same.
2. Games are held every year.
3. I've lived in Lon Don for a long time before I met my sister.
4. How long have you learned Aerobics?
5. If the weather is nice, We will play soccer.
6. She was not tired but she went to bed early.
7. Look, they are having a cup of tea and sandwiches.
8. If there are no taxis, we will have to walk there.
9. Thank you so much for the birthday present.
10. I am interested in films for children.
11. My mother rewarded me with a new pen because of my hard study last week.
12. Potatoes were grown in the field last year.
13. If today is Sunday, I will go to visit my brother.
14. The husband died five years ago and left no money with three children.
15. I am looking forward to your letter soon.