Gingival a. pertaining to the cheek
O b. pertaining to the gum
O c. substance that induces vomiting
O d. hypoglossal
O e. absence of the jaw

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)

How how am i supposed to know