The answer is C. 42% of smokers smoked their first cig in their teens.
Answer:
Three layers of tissue form the heart wall. The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium.
Answer:
D
Explanation:
Sarcolemma also known as sarcomere is a functional unit of the muscle fiber.
The human brain has up to 100 billion neurons (nerve cells)
Answer: Essential body fat is about 3% for men and 12% for women. However, research suggests that for best health and fitness men's body fat should range between 10-18%, and the women's range is 15-23%. Being over-fat, or having a high ratio of body fat to lean body mass, is associated with a higher risk for chronic disease.
Explanation:
