Which two body systems work together to keep your body working properly? a. digestive system and nervous system

b. cardiovascular system and skeletal system

c. respiratory system and digestive system

d. respiratory system and cardiovascular system

It is very important to stay hydrated. your body needs it for may things for cells, tissues, your organs and etc. water also with your temperature that way you don’t get a headache etc. i bet if you look it up there will be a lot of things you can learn.

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.