13. Drug tolerance is when:
A. the body reacts negatively to a drug.
B. a drug does not produce the same effects over a period of time.
C. a person feels physical symptoms if they stop taking a drug.
D. a person has a strong craving for a drug.
__________________________________________
14. Which of the following drugs would be considered a stimulant?
A. Valium
B. heroin
C. methamphetamine
D. aspirin