English exercises plural nouns

English exercises plural nouns. Fill in the gaps with the plural nouns in English for the provided singular nouns in bold.
1. How many have you visited? country
2. I saw two on the way here. wolf
3. Where are my ? key
4. There are twenty-five short in this book. story
5. Buy me three kilos of , please. kilo / potato
6. I'd like two tooth-, please. brush
7. Have you got any against him? proof
8. Those are really nasty. fly
9. I can see nothing but and of . roof / leaf / tree
10. Try to put it all on these two . shelf
11. There are no in the woods. cuckoo
12. I will keep your . watch
13. Boys will be . boy
14. Many soldiers lost their during this war. life
15. I have got two . handkerchief