If the most health-conscious among us have such deep swings in our shut-eye levels throughout the year, how much sleep are the rest of us losing?

如果连我们当中最注重健康的人一整年的睡眠水平都有这么大的波动，那么我们其他人会损失多少睡眠呢？

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It was specifically observed that the left side of the brain was more active during deep sleep.

人们特别注意到，在深度睡眠时，左脑更加活跃。

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It usually happens in the first few hours of sleep in the period called deep sleep.

它通常发生在睡眠的最初几个小时，这个阶段被称为深度睡眠阶段。

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But think of the various periods during the night in which you are in a deep, deep dreamless sleep.

但请设想你处在这样的夜晚,你处于熟睡，安枕无梦。

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It took a long time for the disposal squad to make the bomb safe and during that time, the Ross family had to sleep deep down, on the platforms of Southgate Tube station.

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Excessive alcohol consumption disrupts the 'REM' (Rapid Eye Movement) stage of deep sleep to ruin a night's rest, according to the UK Department of Health.

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Lulled by the silence of the carriage and the prospect of alpine rail travel, I fall into a deep, childlike sleep.

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