Section 2 STRUCTURE, page 268

Find mainverb
Answer :
6. of, in
7. have
8. have , are
9. are, iis
10. was
11. is, will be
12. must
13. at, as
14. is
15. who
16. would be
17. is
18. its
19. are known
20. are
21. is
22. is
23. is
24. is
25. may