Most people require between 7 and 8 hours each night. If needed, set a bedtime reminder alarm on your alarm clock.

大多数人每晚需要7-8小时睡眠，如果需要的话，在你的闹钟上设置一个睡前提醒闹铃。

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Xiaofan, a smart boy from Shenzhen, used to have difficulty in getting up on time, and his alarm clock was of no use at all.

小凡，一个来自深圳的聪明男孩，曾经很难按时起床，他的闹钟根本没用。

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On a usual day, Miranda jumped out of bed even before the alarm clock could ring.

和往常一样，米兰达在闹钟响之前就从床上跳了起来。

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Revelations waited for them like all the silent seconds on a digital alarm clock before the shrieking starts or else like a land mine.

NPR: Excerpt: 'Estrellas y Rascacielos'

She kept the alarm clock on the dresser wound, and accurate to the minute by the wireless morning and evening.

NEWYORKER: The Woman of the House

Most importantly, because Apple did not put an alarm clock app on the iPad.

FORBES: iPad Developer Makes Thousands Because Apple Didn't Include An Alarm Clock App