Viruses that infect animals can mutate to infect humans, often with lethal results
True or false

Which of these is a fact about performance enhancing drugs? a. steroids lack addictive properties. b. steroids use can cause dangerous side effects. c. it is safe to use steroids when working out. d. a person can get in legal trouble for using steroids.

Active immunity refers to: a. the defenses people are born with. b. temporary immunity granted from another source. c. immunity gained through immunization and exposure to diseases. d. natural immunities that protect humans from other animal diseases

Dark clothing enables sweat to be evaporated on the skin's surface very quickly. loose light tight