7.What is the main function of the heart? to exchange gases
to remove waste materials from the body
to produce red blood cells
to move blood through the body

C or D

Explanation:

I'm not so good at but from what i've learned in school i would say one of those

Very sorry

fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges. the core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in.

i believe it is true.