单语范例（未经PONS编辑处理）
One theory is that the warming and dizzying sense of alcohol before bedtime may help some sleep, thus putting a cap on the night.
en.wikipedia.org Hot chocolate is traditionally a bedtime drink but this contains high levels of xanthines (caffeine and theobromine), which are stimulants and so may be counter-productive.
en.wikipedia.org Students are then free until their fixed bedtimes.
en.wikipedia.org One stays awake one whole night and day, then goes to bed 90 minutes "earlier" than usual and maintains the new bedtime for a week.
en.wikipedia.org He recalls that, at bedtime, he would take the small radio that he had hidden beneath his pillow and began listening.
en.wikipedia.org