This is the VOA Special English Education Report.
这里是美国之音慢速英语教育报道。
Surveys of American teenagers find that about half of them do not get enough sleep on school nights. They get an average of sixty to ninety minutes less than experts say they need.
对美国青少年的调查发现，他们中大约有一半的人上学期间睡眠不足，他们的睡眠时间比专家所说的充足睡眠时间平均少60到90分钟。
One reason for this deficit is biology. Experts say teens are biologically programmed to go to sleep later and wake up later than other age groups. Yet many schools start classes as early as seven in the morning.
睡眠不足的原因之一是由于生物钟。专家称，从生理上来说，青少年比其他人群睡得晚也起得晚，然而，很多学校早上7点钟就开始上课了。
As a result, many students go to class feeling like sixteen-year-old Danny. He plays two sports, lacrosse and football. He is an active teen -- except in the morning.
所以，很多学生上课的感觉就跟16岁的丹尼（Danny）一样。丹尼喜欢玩曲棍球和足球，他是个活跃的少年--除了在早上。
DANNY: "Getting up in the morning is pretty terrible. I'm just very out of it and tired. And then going to school I'm out of it, and through first and second period I can barely stay awake."
丹尼：“早上起床是非常痛苦的，我昏昏沉沉的，很困。然后迷迷糊糊地去上学，第一二节课勉强保持清醒。”
Michael Breus is a clinical psychologist with a specialty in sleep disorders.
迈克·布劳斯（Michael Breus）是睡眠障碍方面的临床心理学家。
MICHAEL BREUS: "These aren't a bunch of lazy kids -- although, you know, teenagers can of course be lazy. These are children whose biological rhythms, more times than not, are off."
迈克：“他们不是一群懒惰的孩子，尽管你知道青少年的确有点懒。那些是孩子的生物规律，很多时候就是这样。”
Teens, he says, need to sleep eight to nine hours or even nine to ten hours a night. He says sleepy teens can experience a form of depression that could have big effects on their general well-being. It can affect not just their ability in the classroom but also on the sports field and on the road.
他称，青少年每晚需要8到9个小时，甚至到10个小时的睡眠。昏昏欲睡的青少年会感觉到一种状态不佳，这会给他们日常生活造成很大的影响，不仅会影响他们课堂上的学习能力，也会影响他们在运动场上的发挥，还会在路上造成危险。
Michael Breus says any tired driver is dangerous, but especially a teenager with a lack of experience.
迈克称，任何疲惫的司机都是危险的，特别是一个缺乏驾驶经验的青少年。
So what can schools do about sleepy students? The psychologist says one thing they can do is start classes later in the morning. He points to studies showing that students can improve by a full letter grade in their first- and second-period classes.
学校能为这些昏昏欲睡的学生做些什么呢？心理学家称，他们能做的就是推迟早上上课时间。他指出，研究结果显示，学生们能通过第一、二节课的优异表现得到改善。
Eric Peterson is the head of St. George's School in the northeastern state of Rhode Island. He wanted to see if a thirty-minute delay would make a difference. It did.
艾瑞克·彼得森（Eric Peterson）是美国罗德岛州东北部圣乔治学院的校长，他想看看推迟30分钟上课是否可以有所改善，结果确实如此。
He says visits to the health center by tired students decreased by half. Late arrivals to first period fell by a third. And students reported that they were less sleepy during the day.
他称，去健康中心的疲劳学生减少了一半，第一节课迟到的学生下降了三分之一，而且，学生说他们白天更少犯困。
Eric Peterson knows that changing start times is easier at a small, private boarding school like his. But he is hopeful that other schools will find a way.
艾瑞克知道，像他这种小私立寄宿学校改变上课时间更容易些，但是他希望其他学校能找到一种解决这件事的办法。
ERIC PETERSON: "In the end, schools ought to do what's the right thing for their students, first and foremost."
艾瑞克：“归根结底，学校要做对学生有利的事情，这是最首要的。”
Patricia Moss, an assistant dean at St. George's School, says students were not the only ones reporting better results.
圣乔治学院的助理主任帕特里夏·莫斯（Patricia Moss）称，学生不是唯一（对推迟上课时间）反应不错的人群。
PATRICIA MOSS: "I can say that, anecdotally, virtually all the teachers noticed immediately much more alertness in class, definitely more positive mood. Kids were happier to be there at eight-thirty than they were at eight."
帕特里夏：“事实来讲，所有的老师都马上发现，他们的学生在课堂上反应更机敏，态度也确实更积极。孩子们更喜欢8:30来上课而不是8:00。”