Answer:
d. 60
Explanation:
Both the American College of Sports Medicine and the U.S. Department of Health and Human Services recommend at least 60 minutes of exercise daily for youth under the age of 18. This has been determined to be a good daily dose of exercise in order to allow healthy growth and development of youth below the age of 18th. Which is also why Physical Education classes in the United States are mandatory and last 60 minutes.
Diffusion is a _distribution_ process where a solute moves from ahigherconcentration to alower<span>concentration.</span>
HIV or Human Immunodeficiency Virus is a viral infection, which directly attacks Leukocytes (white blood cells). Leukocytes are the cells responsible for fighting infections that break past the skin. If the infection is not controlled it can cause a range of disorder's which form a syndrome called AIDS or Acquired Immunodeficiency Disorder Syndrome. When this happen common infection for such thing as a common cold can turn lethal as the body is unable to fight pathogen's effectively.