(单词翻译:单击)
听力文本：
We waste a third of our lives sleeping.
我们生命中三分之一的时间浪费在睡眠上。
When there doesn't seem to be enough hours in the day, you yearn to be like the former British Prime Minister Margaret Thatcher, who was said to get by on just four hours' sleep a night.
当白天的时间不够用时，我们就会渴望自己能做到和英国前首相玛格丽特·撒切尔一样。据说玛格丽特·撒切尔每天只睡四个小时。
There is a quite a range in the number of hours we like to sleep.
人们习惯的睡眠时长大不相同。
80% of us manage between six and nine hours a night; the other 20% sleep more or less than this.
我们当中80%的人每晚的睡眠时长能维持在6-8小时；其余20%在这个区间还要上下浮动一些。
There is plenty of evidence that a lack of sleep has an adverse effect.
很多证据显示缺少睡眠会带来副作用。
We do not simply adjust to it—in the short-term it reduces our concentration, and if it's extreme it makes us confused and distressed, and turns us into such poor drivers of being drunk.
睡眠缩短，我们不会就能简单地适应。短期缺觉会削弱我们的注意力，而如果缺觉严重我们会变得迷糊甚至忧郁，我们会变得像一个醉驾的司机。
The long-term effects are even more worrying.
而长期缺觉后果会更严重。
Repeatedly getting less sleep than you need over the course of decades is associated with an increased risk of obesity, diabetes, high blood pressure and heart diseases.
如果几十年长期缺觉就有导致肥胖、糖尿病、高血压和心脏病的风险。
But while it might not be possible to train yourself to sleep less, researchers working with the military have found that you can bank sleep beforehand if you plan well in advance.
虽然通过训练让自己少睡觉这招行不通，一些军队中的调查者发现你可以提前补觉。
At the Walter Reed Army Institute of Research they had people go to bed a couple of hours earlier than usual every night for a week.
在沃尔特里德陆军研究所里，实验对象每天早睡几个小时，这样持续了一周。
When they were subsequently deprived of sleep they didn't suffer as much as the people who hadn't had the chance to bank sleep in advance.
之后当他们的睡眠时间遭到压榨时他们感受到的痛苦程度比那些没有提前补觉的人要小。
Questions 16-18 are based on the passage you have just heard.
请根据刚刚听得短文回答16-18题。
16. How much time do most people usually sleep every night?
16.多数人每晚睡多长时间？
17. What could happen if people didn't get enough sleep for a long time?
17.如果长时间缺觉人会怎么样？
