Humans need less sleep than other mammals, yet their slumber is more efficient, said researchers at Duke University in North Carolina. In their study, the scientists researched sleep patterns of hundreds of animals. They discovered humans sleep for shorter periods of time compared to other animals.________________________________美国北卡罗莱纳州杜克大学的研究人员称,相比其它哺乳动物,人类所需的睡眠时间更少,而睡眠更高效. 研究中,科学家研究了成百上千种动物的睡眠模式,他们发现,相比其它动物,人类的睡眠时间更短._________________________
