Q: Fact 1: When the body is hot , sweat is produced to cool the body. Fact 2: Exercise, fever, and heat cause the body's temperature to rise. Given the two facts above, what causes sweat to be produced to cool a person down?

(1). exercise and fever;
(2). wool pants;
(3). the sun;
(4). Movement of an air mass;
(5). shooting stars;
(6). Evaporation;
(7). centralized nervous system;
(8). water vapor;
A:
(1).