Answer:
It is the stuff that you breath
Explanation:
Because if you didn't, you would die... So the benefit of oxygen is not being dead.
Answer:
A
Explanation:
When atherosclerosis narrows the arteries close to your heart, you may develop coronary artery disease, which can cause chest pain (angina), a heart attack or heart failure
<span> An </span>optimal ratio<span> is less than 3.5-to-1.</span>
No this is not true if you start to exercise after a heart attack it can help prevent any other heart attacks