Among american adults, the second most commonly abused type of drug, after marijuana, is

Mucous membranes.. a. cover or line external surface of body. b. line internal body surfaces that are in contact with the environment. c. produce antibodies to combat infection. d. secrete sweat, which has antibacterial enzymes.

Which of the following defines scoliosis? a. a posture disorder characterized by the shoulders being rounded and the back hunched b. a posture disorder in which the spine curves up the back like a snake c. a posture disorder characterized by excessive curvature or arch in the lower back d. none of the above

During polarizacion potassium has a blank charge sodium has a blank charge and calcium has a blank charge