1.
thunderstorm
2.
self-addressed
3.
background
4.
cross-country
5.
post
office
6.
weatherproof
7.
throughout
8.
sister-in-law
9.
bill
of sale
10. everybody
11. checkbook
12. skyscraper
13. overcast
14. all right
15. passerby
16. wristwatch
17. campsite
18. campfire
19. bookstore
20. grown-up