What where the following answers?
Oxidative stress is an imbalance between the production of free radicals (highly unstable molecules that are naturally formed when you exercise and when your body converts food into energy) and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants. Antioxidants such as thiols or ascorbic acid prevent free radicals forming due to oxidation. Some ways our bodies can be exposed to oxidative stress are by having an unbalanced diet, smoking, or sun exposure. Some ways to prevent oxidative stress are having a healthy diet, not smoking, exercising regularly and wearing sunscreen.
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 of the heart. As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.
