大学英语四级选词填空练习（二十九）难度：适中评论：1收藏 3闯关背单词，尽在开心词场！跟玩儿似的不枯燥，没注册怎么能参与呢？The popular notion that older people need less sleep than younger adults is a myth, scientists said yesterday.While elderly people _1_ to sleep for fewer hours than they did when they were younger, this has a(n) _2_ effect on their brains performance and they would benefit from getting more, according to research.Sean Drummond, a. psychiatrist (心理医生) at the University of California, San Diego, said older people a
