The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere's eye stays open and alert.

由睡眠大脑半球控制的眼睛保持关闭，而清醒大脑半球的眼睛保持睁开和警觉。

youdao

When the ache is bad enough it keeps me from sleeping.

疼得厉害的时候，我就睡不着了。

youdao

This can help reduce acid reflux when sleeping, as gravity keeps the acid in the stomach.

因为重力可以让胃酸流回胃里，所以这样有助于在睡觉时防止胃酸倒流。

youdao

Inside, keep your body off the ice or ground (the Inuit put their sleeping blankets on top of a bed of sticks and reeds) and create heat-trapping "loft" (it's what keeps you warm in a sleeping bag) by layering a few small blankets or big trash bags, with leaves or crumpled newspapers in between.

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On nights when they have different bedtimes, Ms. Ellis may take an Ambien sleeping pill, which keeps her from waking up when Mr. Ellis comes to bed later.

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