Variables other than the independent variable on which participants differ are termed variables. They threaten validity.

Your friend goes on an all-mango diet for one month to investigate whether she can make her skin turn orange. which of the following will be most deficient in this diet? a.minerals b.dietary fiber c.amino acids d.vitamins

Name three bad things that can happen to a teenager who has no refusal skills and no self-control:

What is the most common blood type in the u.s.?