The skeletal system, the muscular system, and the nervous system all work together. explain one link between the skeletal system and the muscular system, between the skeletal system and the nervous system, and between the muscular system and the nervous system.

Skeletal and Muscular:
The muscles help move the bones when you need to move your arm to do something like writing something down or raising your hand.

Skeletal and Nervous:
Sensory receptors in joints between bones send signals about body position to the brain.

Muscular and Nervous:
Receptors in muscles provide the brain with information about body position and movement.

Maximal strength i believe

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)