Ais a rigid layer that surrounds a plant cell, providing structural support.

the real answer is b. scintillation counter

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.

i think it is d. objects resist changes in their state of motion.