用方框中所给短语的适当形式完成短文。

clear your mind   wake up   take a nap   a short time   how long

    Many students aren't getting enough sleep at night, which means they end up feeling sleepy during class. during the day may be a solution.

    According to Forbes, a mid-afternoon nap can , increase your energy and help you study even better. But should a nap last? The proper time should be between 10 and 30 minutes, Peter Venn, a sleep expert said.

    Sleeping for , such as five minutes or so, is not helpful. That's just not enough time to rest. But if you sleep for too long, you may feeling uncomfortable.