VOA慢速英语:What Causes Jet Lag and How to Avoid It

短语讲解：

1. In fact, light is the most powerful environmental signal for re-setting our biological clock.

in fact 实际，事实上
例句：In fact these clauses were never enforced. 
这些条文事实上始终没有得到执行。 

2. A circadian rhythm is a 24-hour cycle, a series of events or actions that happen in the same order, over and over again.

over and over again 一再地; 来回来去; 再三再四
例句：Over and over again he drew that face. 
他一次又一次地画着那张脸。 

3. They have a firefly gene engineered into these flies, so that when these cells are active, they actually, literally light up in the brain and we can measure that activity.

light up 照亮; 点烟
例句：It' s time to light up. 
该点灯了。 

4. He says using light to temporarily reset your biological clock before you travel could help to reduce symptoms when you arrive at your final stop.

arrive at 到达; 来到
例句：I' ll get the sack if I arrive at the office late ! 
如果上班迟到，我就得被开除。 

5. But it can help you to start thinking of the time at the other end of the flight.

think of 考虑; 想起
例句：I can think of two scenarios.
我能想到的有两种情况。

6. During your flight, get up and walk around or stretch every so often.

get up 起床
例句：I'll get up early,so as to be ready when you come. 
我早些起床，以便你来的时候我就准备好了。