How the heart works
The heart is part of your body’s circulatory system. It’s made up of the atria, ventricles, valves, and various arteries and veins. The main function of your heart is to keep blood that’s full of oxygen circulating throughout your body. Because your heart is crucial to your survival, it’s important to keep it healthy with a well-balanced diet and exercise, and avoid things that can damage it, like smoking.
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<span>the answer is b. chromosome y. </span>
If the mother is Drinking, Smoking, and doing drugs while she's pregnant those are all unhealthy and can cause the baby to have health problems.
