What is the differences between natural and unnatural selection

Which statement is true about common childhood infectious disease? a. children should always be given antibiotics to treat an infectious illness. b. frequency of infectious illnesses usually increases as children grow older. c. having a minor infectious illness weakens a child's immune system. d. infectious illnesses are usually mild and require no medication.

Jim and phil are changing the oil in jim’s car. jim is trying to remember all the actions involved in changing the oil. phil is trying to remember the first time he ever changed the oil in his car. jim is trying to recall a memory and phil is trying to recall a(n) memory.

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.