在电池供电的实时系统中，需要考虑到两个约束：一个是实时系统中任务的截至时间，另一个就是能量问题。

There are two constraints need to addressed in battery-powered real-time systems, one is the deadline of the task in real-time systems and the other is energy issue.

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截至2016年，美国高中高年级学生说他们在空闲时间里平均每天要花6个小时的时间写短信、上社交媒体以及上网。

By 2016, the average American high school senior said they spent six hours a day writing text messages, on social media, and online during their free time.

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确立一个截至日期和时间，在这之后就不能更改旧服务器上的信息了。

Establish a cutoff day and time after which information on the old server can not be changed.

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