S2. What are the things the author think teachers should do but haven’t done______.

A．Find a quiet place to study.
B．Change the conditions of his room.
C．Find a more comfortable place to study.
D．Avoid distractions while studying in his room.

A．Jogging is better than the other types of exercise.
B．Heart disease is no longer an American national problem.
C．Jogging can be harmful if the runner is not properly prepared.
D．Warm-up suits are better than gym shorts and T-shirts for joggers.