Answer:
They are at higher risk because of hormones. During adolescence, you go through different hormonal changes, including sexual ones. These sexual changes may result in developing different urges such as masturbation. However, the problem comes with a lack of proper sexual education and how most of their knowledge on sex is based off of myths perpetuated by peers. So it's really a lack of education on sexual reproduction and the transmission of diseases.
The answer to this question is the scientific method. A scientific method is a technique used in gathering new data or knowledge which ia consisting of testing, observation, measurement, and forming of hypothesis or conclusion. The scientific method is used to test hypothesis and to help scientist to solve or form a solution to the problem.
B.) Blood Vessels.
The circulatory system deals with anything that circulates blood throughout the body to distribute Oxygen into different parts of the body.