As we fall asleep the amplitude of brain waves slowly becomes greater.进入睡眠状态时，我们的脑电波振幅慢慢变大。After changing the bed, I would fall asleep quickly.换了床单，我很快就能睡着。He was wont to fall asleep after supper.他老是吃完晚饭就打盹。...
How monogamy fares during this epoch, therefore, only occupies him very briefly.所以, 他只是非常简单地论述了一下一夫一妻制在这一时期的命运.People still opt for monogamy and marriage.人们仍然选择一夫一妻制。McLennan knew only three forms of marriage: polygyny, ...