Ответ:
1. bush; bushes (in reference to various types of bushes or a collection of bushes)
2. children
3. church; churches (in reference to various types of churches or a collection of churches)
4. feet
5. geese
6. halves
7. heroes
16. shelves
17. switches
18. thieves
19. tomatoes
20. teeth
21. watches
22. wives
23. wolves