Which of the following is used to kill germs?
a. washing.
b. sanitizing.
c. rinsing.
d. air drying.?

B, sanitizing.
When you use hand sanitizer or hand soap, you are using chemicals to kill off the bacteria. Washing/rinsing your hands only moves the bacteria, and doesn't kill them. Air drying your hands does not in anyway kill germs. 

Iwould say being around others who are not drug free is the wrong step because your peers are likely to influence any new or past habits

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)