According to the author, which of the following re...

Câu hỏi: According to the author, which of the following reasons disrupt travelers’ sleep?

A Travelers try to sleep between 3-5 p.m. 

B Travelers’ attention is reduced by 75 percent.

C  The traveler’s internal circadian clock has to adjust to patterns of light and activity.

D Travelers fly in the natural direction of their internal clock