According to the National Sleep Foundation,

　　41 should sleep twelve to eighteen hours

　　42

　　of every twenty-four. With a gradual

　　43

　　to twelve to fourteen hours for toddlers(初学走路的孩子) one to three; eleven to thirteen hours for

　　4

　　three to five; and ten to eleven hours for schoolchildren

　　45

　　five to ten.

　　But things get really

　　46

　　at adolescence. Not only do teenagers need more sleep than

　　47 __---eight and a half to nine and a quarter hours a night, according to the sleep foundation - but the times

　　48

　　which they get sleepy and are able to awaken

　　49

　　and feel rested shift in a

　　50

　　that does not match to the

　　51

　　times at most schools.

　　Sleep studies have shown that the typical teenager does not fall asleep readily before 11 p. m. or later.

　　52

　　many have to get up by 6 a. m. or

　　53

　　to get to school for a class

　　54

　　starts at 7:30 or 8 a.m. More than a few

　　55

　　off during that class, and often the

　　56

【2017高考英语一轮专项训练：完形填空及阅读理解（8）含答案】相关文章：

★ 2014高考英语（新人教版）一轮基础训练（5）A、B卷（附答案或解析）

★ 常熟市2014高考英阅读理解语一轮（暑假）训练题（12）及答案

★ 四川省广安市2014高考英语一轮基础训练题（2）及答案

★ 常熟市2014高考英阅读理解语一轮（暑假）训练题（9）及答案

★ 贵州省贵阳市2014高考英语（新人教版）一轮阅读训练（17）附答案

★ 2017届高考英语二轮复习大题冲关秘籍语法填空：解题技巧（含解析）

★ 重庆市2014高考英语阅读理解一轮（精品）训练题（19）附答案

★ 2017高考四川省广安市英语阅读理解一轮系列训练：22（含解析）

★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练：第20组（含解析）

★ 【课堂新坐标】2017届高考英语（通用版）二轮复习书面表达专题训练：Ⅱ卷强化增分练 训练2（含解析）