abbreviation
1. saturable reactor
2. seaman recruit
3. sedimentation rate
4. self-rectifying
5. often not capitalized semantic reaction
6. senate resolution
7. sensibility reciprocal
8. service record
9. shipping receipt
10. short rate
11. often not capitalized small ring
12. social-revolutionary
13. sound ranging
14. special regulation
15. star route
16. stateroom
17. stimulus-response
18. storage room
19. subject ratio
20. supplementary regulation