A) life in the school was very stressful
B) disease could be caused by psychological factors
C) the good students were likely to fall ill
D) stress often made students unhappy

A) They adjust themselves timely in line with their physical conditions.
B) People increase or lower the body temperature by sweating.
C) People’s hearts pound to compensate when the blood pressure goes up.
D) Our natural state is not a steady one.