题目内容：

Imagine the first days in a new time zone. Slow to respond to the _______, your body clock is confused. You’re sleepy all day, but when it’s time for bed, you can hardly fall asleep. Obviously you are _______ jet lag（时差反应）.

Travelers have traditionally fought this _______ with sleeping pills or alcohol. There are actually healthier ways that can work just as _______.

For example, the moment you get on the airplane, start _______your biological block to the destination’s time. If it’s daytime in your destination, try to stay _______. Walking around the cabin（客舱） can be of help. When it’s nighttime, try to sleep. In that case, eat before the flight, _______an empty stomach will prevent you from sleeping. These tips will help you start a new _______ of sleep and wakefulness.

1.A.flight B.change C.demand D.climate

2.A.suffering from B.working on C.looking into D.leading to

3.A.danger B.problem C.waste D.fear

4.A.briefly B.slowly C.suddenly D.effectively

5.A.checking B.sending C.adjusting D.stopping

6.A.awake B.alone C.hungry D.calm

7.A.though B.so C.whole D.or

8.A.understanding B.cycle C.research D.trend