Question

7．Teenagers believe anything is possible if thy study hard．But they often forget to think about healthy diets（饮食），enough sleep time and exercise．In fact，these things are really important for them to keep fit．
  It is important for teenagers to get enough energy．Teenage girls need about 2200 calories a day while boys need a bit more-doctors suggest 2800 for teenage boys 50% of their calories should come from healthy food-rice，begetables and fruit．People often say an apple a day keeps the doctor away．Teenagers also need to drink a lot of water，6 to 8 glasses a day．Drinking enough water will improve their skin．
  Teenagers usually need eight to ten hours'sleep at night，but many Chinese teenagers do not get enough sleep．A report shows that without a good night's sleep，teenagers seem to be weaker than they should be．Too much homework is not the only reason why teenagers stay up late．Some watch TV or play computer games late into the night．Teenagers should develop good study habits．So some clever students never study late，but they are able to work well in class．
  Exercise is something that can help them．Experts suggest that teenagers should spend at least 30 minutes exercising a day，five times a week．They will feel relaxed when they exerxise．It can even help them sleep better at night．

46．How many things are important for teenagers to keep fit？B
A.2                    
B.3                  
C.4
47．Half of their calories should come fromA．
A．rice，vegetables and fruit  
B．rice，vegetables and meat 
C．rice，vegetablesand water
48．The last paragraph（段）mainly talks aboutC．
A．sleeping better      
B．basic energy      
C．necessary exercise 
49．Which of the following is NOT true？A
A．Boys need much more calories than girls
B．Teenagers need to drink 6 to 8 glasses of water a day
C．Some clever students never study late
50．The passage tells teenagers how toC
A．eat and drink well      
B．study hard    
C．keep fit．

Answer 1

分析 全文大意：
青少年认为如果他们努力学习一切皆有可能．但是他们常常忘记了考虑健康饮食、充足的睡眠时间和锻炼．实际上这些事情对他们的健康的确很重要．对青少年来说获取充足的能量很重要．十来岁的女孩一天大约需要2200卡路里的能量，而十来岁的男孩稍微多一点，医生建议2800卡路里的能量．50%的卡路里应该来自健康饮食：米饭、蔬菜和水果．人们经常说"一天一苹果，不用请医生"青少年也需要喝大量的水，一天6至8杯．和足够的水能改善他们的皮肤．青少年晚上通常需要8到10小时的睡眠时间．但是许多中国青少年睡眠不足．一项报告表明没有好的夜间睡眠．青少年身体状况看起来比正常情况要差．大量的家庭作业并不是青少年熬夜的唯一原因．一些青少年看电视或玩电脑游戏到深夜．青少年应养成好的学习习惯．所以一些聪明的学生从不学到很晚，但是他们在课堂上学得很好．锻炼也能有助于他们的身体．专家建议青少年应一周五次，每天至少锻炼30分钟．当他们锻炼时他们会感到放松．锻炼甚至有助于他们晚上的睡眠．

解答 答案：
46．B      细节理解题      根据第一段中But they often forget to think about healthy diets（饮食），enough sleep time and exercise．In fact，these things are really important for them to keep fit．"但是他们常常忘记了考虑健康饮食、充足的睡眠时间和锻炼．实际上这些事情对他们的健康的确很重要"可知对青少年来说保持健康有三件事即饮食、睡眠和锻炼．故选B
47．A      细节理解题      根据第二段Teenage girls need about 2200 calories a day while boys need a bit more-doctors suggest 2800 for teenage boys 50% of their calories should come from healthy food-rice，vegetables and fruit．"十来岁的女孩一天大约需要2200卡路里的能量，而十来岁的男孩稍微多一点，医生建议2800卡路里的能量．50%的卡路里应该来自健康饮食：米饭、蔬菜和水果"可知一半的能量来自米饭、蔬菜和水果，故选A．
48．C      段落大意题      根据最后一段的第一句Exercise is something that can help them"锻炼也能有助于他们的身体"可知这一段主要讲述锻炼的必要性．故选C
49．A      细节理解题      通读全文第二段中提到Teenagers also need to drink a lot of water，6 to 8 glasses a day可知青少年一天需要6至8杯水，故B项正确；第三段中提到some clever students never study late可知一些聪明的学生从不学到很晚，故C项描述正确，最后根据第二段Teenage girls need about 2200 calories a day while boys need a bit more-doctors suggest 2800 for teenage boys"十来岁的女孩一天大约需要2200卡路里的能量，而十来岁的男孩稍微多一点"可知男孩需要的卡路里比女孩稍微多一点，并非多得多，故A项不正确，故选A
50．C     主旨大意题      根据短文第一段Teenagers believe anything is possible if thy study hard．But they often forget to think about healthy diets（饮食），enough sleep time and exercise．In fact，these things are really important for them to keep fit．"青少年认为如果他们努力学习一切皆有可能．但是他们常常忘记了考虑健康饮食、充足的睡眠时间和锻炼．实际上这些事情对他们的健康的确很重要"，然后在接下来的三段中分别从饮食、睡眠和锻炼三个方面介绍如何保持健康．可知短文主要告诉青少年如何保持健康，故选C．

点评 这是一篇健康环保类的说明文．做题时先把文章快速通读一遍抓住其大意．该题涉及细节理解题和主旨大意题，要结合问题从文中找到与之相关的句子，抓住关键词和细节进行选择，和选项进行比对快速选出答案．