Most of usdrift from our waking lives into predictable cycles of deep, non-REM sleep, followed by dream-filled rapid-eye-movement (REM) sleep.

我们大多数人会从清醒状态转入预料中的周期：深度非快速动眼睡眠（non-REM），之后是充满梦境的快速动眼（REM）睡眠。

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In between cycles of REM sleep, we have non-REM sleep, which includes deep or 'slow-wave' sleep.

在快速眼动睡眠周期之间，我们还有非快速眼动睡眠，包括深度睡眠和慢波期睡眠。

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In the deeper stages of non-REM sleep brain activity is slower.

在非快速眼动睡眠期的更深层阶段，脑活动较慢一点。

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