1. demonstrate
4. general population
7. by way of
8. oral
11. speculate
13. to be associated with
14. sedating, calming, soothing
17. sign
18. adj. meaning "certain" that is always used in front of a noun
20. accepted
21. able to be seen or be noticed
24. abstinent
26. calming
28. to reach the highest value, level, rate, etc.
30. completely
32. recommend
33. activate
34. rule out
36. essential
37. reappearance
38. bring back to the original condition
39. very difficult and requiring a lot of effort