2013年12月大学英语四级仔细阅读习题及答案

2013年12月大学英语四级仔细阅读习题及答案 （一） Judging from recent surveys,most experts in sleep behavior agree that there is virtually an epidemic (流行病) of sleepiness in the nation. “I can'tthink of a single study that hasn't found Americans getting less sleep thanthey ought to,” says Dr. David. Even people who think they are sleeping enoughwould probably be better off with more rest. 　　The beginning of our sleep-deficit (睡眠不足) crisis can betraced to the invention of the light bulb a century ago. From diary ent