Oxygen from the air enters the blood stream at what location? A) Aorta
B) pulmonary vein
C) alveoli
D) pulmonary artery

c. alveoli.

Explanation:

the oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place of the transfer of oxygen into the blood through simple diffusion.

alveoli

Explanation:

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;

producers: apple trees, potatoes, carrots, grains, acorns, cabbage, grass, corn, lettuce

consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls