Помогите решить. Нужно С и Е

Question

Помогите решить. Нужно С и Е

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Answer 1

C.
16. to join.
17. cleaning.
18. use.
19. buying.
20. taking.
21. to starting.
22. wondering.
23. to send.
24. donate.
25. to go.

E. 
31. protection. 
32. disappearance.
33. existence.
34. reference.
35. donation.