In what circumstances would you use each resource at your home?

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)

My funny joke is my friend can no roll over

Answer active artificial immunization;

Answerviruses;