1. I asked my friend when we would go to the computer club.
2. The teacher inquired if we had already switched off our cell phones.
3. He wondered what I was doing at 6 o’clock the previous day.
4. My mother resented when it had happened.
5. The author of the article was interested why young people didn't like to read books.
6. She asked me how long I had been using that mailbox.
7. My parents inquired if I had sent that parcel to the granny by her birthday.
8. I inquired if you had really got his SMS the previous day.
9. My friend wondered if I was going to watch that reality-show.
10. I asked my fellow-student if he had finished his investigation by week-end.
a girl - girls
a car - cars
a robot - robots
a puzzle - puzzles
a doll - dolls
an elephant - elephants
a bike - bikes