Answer:
1. your answer is prolly correct (not 100% sure about this one)
2. your answer is correct
3. your answer is correct
4. C, no apostrophes
5. your answer is correct
6. the first "diver's" you have correct, the second "divers" should not have an apostrophe
7. C, no apostrophes
8. your answer is correct
9. C, no apostrophes
10. not correct, it should be "skydiver's"
hope this helps!