A __________ lens is thinner at the middle than at the edges and causes the light to diverge or spread

Narrowing of the valves within the heart is best described as:

A) stenosis. B) cardiac hypertrophy. C) dysrhythmia. D) pulmonary edema.

__________ remove heat when discharged onto the surface of combustible materials. The heat is absorbed from the surface of the burning material, thereby lowering its temperature below the autoignition point

a. Halocarbons b. Water molecules c. Dry chemicals d. Carbon dioxide molecules