目前，我们大总分青少年朋友都是睡眠不够的。足够的睡眠是一个学生在第二天的考试或运动中取得好成绩的基本前提条件，而青少年学生每天至少需要8个半到9个小时的睡眠时间，很明显目前很少学生达到这个水平。在此英语作文大全提醒广大学生朋友，特别是刚上七年级的学生，要写好英语作文一定要保证每天的睡眠时间。 Most teens need about 8½ to more than 9 hours of sleep each night. The right amount of sleep is essential for anyone who wants to do well on a test or play sports without tripping over their feet. Unfortunately, though, many teens don't get enough sleep.
Why Aren't Teens Getting Enough Sleep? Until recently, teens were often given a bad rap for staying up late, oversleeping for school, and falling asleep in class. But recent studies show that adolescent sleep patterns actually differ from those of adults or kids. These studies show that during the teen years, the body's circadian rhythm (sort of like an internal biological clock) is temporarily reset, telling a person to fall asleep later and wake up later. This change in the circadian rhythm seems to be due to the fact that the brain hormone melatonin is produced later at night for teens than it is for kids and adults. This can make it harder for teens to fall asleep early. These changes in the body's circadian rhythm coincide with a time when we're busier than ever. For most teens, the pressure to do well in school is more intense than when they were kids, and it's harder to get by without studying hard. And teens also have other time demands — everything from sports and other extracurricular activities to fitting in a part-time job to save money for college. Early start times in some schools may also play a role in this sleep deficit. Teens who fall asleep after midnight may still have to get up early for school, meaning that they may only squeeze in 6 or 7 hours of sleep a night. A couple hours of missed sleep a night may not seem like a big deal, but can create a noticeable sleep deficit over time.英语作文【在百度搜索更多与“青少年学生需要多长的睡眠时间？英语作文”相关英语作文】