D. Fats provide 9 calories
Answer:
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. The pulmonary vein empties oxygen-rich blood, from the lungs into the left atrium.
Explanation:
hope this helps...
and if u didn't get it its veins...
Heart Attack is a real emergency
My second choice is Blood
Answer:
proteins nutrient is used to build and maintain all of the cells and tissues in the body...
I hope it helps !!