Do you know there are five stages of sleep? 你知道睡眠分五个阶段吗？

　　During the first four stages of sleep, the human body and brain take a rest. 在睡眠的前四个阶段，人的身体和大脑休息。

　　But during the fifth stage of sleep, the brain works hard, so we have dreams. 但在第五个阶段，大脑很努力地工作，所以我们做梦。

　　If you always takes one hundred minutes to experienced all five stages of sleep, what happens then? 如果你总是花100分钟去经历睡眠的五个阶段，那么接下来会发生什么呢？

　　We'll repeat this five stages again. 我们将再次重复这五个阶段。

　　People usually have three to four sleep cycles during their night sleep. 在夜间睡眠中，人们通常有三到四个睡眠循环。

　　People can remember their dreams if they wake up during the fifth stage. 如果人们在第五个阶段醒来，他们就能记住自己的梦。

　　But they forget their dreams during the next cycle of sleep. 但他们会在下一个睡眠周期中忘记了自己的梦。