The main function of the cardiovascular system is therefore to maintain blood flow to all parts of the body, to allow it to survive. Veins deliver used blood from the body back to the heart. When your blood circulates through your digestive system, it picks up nutrients your body absorbed from your last meal. So it is a very critical part of the digestive system since the body can't absorb nutrients to survive
perhaps you live by a pond.The water,wind, and tempature are all antibiotic factors.The fish,frogs,and bugs are all living so they are the biotic factors.
The pH scale measures the concentration of how acidic or basic something is. The lower the number below 7, is acidic. Above 7 is basic. 7 is waters purest form.
A physical change is basically a body change so like if a crayon is solid then sits in the sun for a long time it melts away that’s a physical change because it changes its physical appearance