små engelsk sætninger

Jeg har oversætte følgende sætninger,men jeg er ikke sikker på om det er rigtigt, hvis der nogen der kan kigge på det.

omskriv følgende sætninger til flertal
1.The chair was too expensive.The chairs were too expensive.
2.Your book is very interesting. Yours books are very interesting.
3. The stranger looked at her curiously. the strangers loóked at hers curiously.
4. The novel we read was boring. the novels we read were boring.
5. The door was locked at ten o'clock. the doors were locked at ten o'clock.
6. the shop was fashionable ten year ago. the shops were fashionable ten years ago.
7. the boy has many friends. The boys have many friends.
8. The city was very old. The cities were very old.
9.the country I visted was rather poor. The countries I visted were rather poor.
10. The dico was full og yongsters. The dicos were full of youngsters.