听力原文:W: Doctor, I haven't been able to get enough sleep lately, and I'm too tired to c
M: Well, you know, spending too much time indoors with all that artificial lighting can do that to you. Your body loses track of whether it's day or night.
Q: What does the man imply?
(13)
A.The woman is making too big a fuss about her condition.
B.Fatigue is a typical symptom of lack of exercise.
C.The woman should spend more time outdoors.
D.People tend to work longer hours with artificial lighting.