Each sleep cycle lasts 90 minutes. Set your alarm clock to go off after a multiple of an hour and a half, and it will be easier to wake up.

每一轮的睡眠持续90分钟，所以在设定闹钟的时候时间设置应为1.5小时的倍数，这样更容易把你叫醒。

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Studies show that even the tiny light from a digital alarm clock can disrupt a sleep cycle .

有研究显示，即便电子闹钟传来的微弱亮光都能打乱一次睡眠周期。

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