This is called stage 1 sleep.

这被称为第一阶段睡眠。

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Your brain waves slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves 1 sleep.

你的脑电波频率变慢且变得十分有节奏，仅变慢的一点，以第一睡眠期的阿尔法节律波动，而不是更快的波率。

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According to a 2008 poll by the National sleep Foundation, 28% of the 1, 000 respondents said sleepiness interferes with their daytime activities at least a few days each month.

美国国家睡眠基金会2008年的调查结果显示，在1,000位受访者中，有28%的人表示瞌睡会影响他们白天的工作，每个月至少有几天会出现这种情况。

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