Question

Did you know that sixty percent of your body weight is water？However，a loss of only two percent of this water through dehydration(脱水) during exercise can significantly affect your performance. The more you sweat，the more your exercise performance declines，unless you drink enough to replace your loss of fluids.

When you lose too much water，you can overheat quite easily，especially in a warm environment. But this is not the only problem you may be faced with. Dehydration leads to your heart pumping much faster，which means exercise becomes more difficult and requires more effort. Despite these problems，however，many of us simply do not take enough fluids in when we head for the gym or set out on a run.

So why is this? How do we manage to lose so much water without simply drinking more to replace it？Well，it is easier than you think. When we are at rest，we quickly become aware that we are thirsty and will put that right by having a drink. When we exercise，on the other hand，our thirst mechanism(结构) does not work as effectively，so we don't notice early enough that we are actually thirsty. In fact，we only start to feel thirsty when we have already lost around two percent of our body weight.

Another problem is that，the more dehydrated we become during exercise，the more difficult it is to prevent further dehydration—because our stomachs become intolerant to fluids and we do not absorb water properly，just when we need it most.

The key thing about fluids and exercise is to manage your intake properly—regular small amounts are better，and some should be drunk before the period of exercise begins. You also need to match your intake to the sort of exercise you are doing. For instance，for one hour of exercise，such as taking part in a 10 km run，you need to drink about two extra liters of water. For longer periods of exercise，sports drinks are recommended.

1.We know from the text that during exercise，dehydration________.

A. can be easily avoided

B. will lead to poor performance

C. can cause many health problems

D. will be controlled whenever we drink again

2.Why do people suffer from dehydration easily during exercise?

A. Their thirst mechanism stops working.

B. Their focus is on the exercise.

C. Their thirst response is slow.

D. Their stomachs are full.

3.When exercising，you are advised to________.

A. have regular breaks

B. drink water accordingly

C. drink sports water in advance

D. have at least two liters of water

4.What would be the best title for the text?

A. Keep fit

B. Say no to sports!

C. Time to get drinking!

D. Ways to avoid dehydration

Answer

概括文章标题☞D 选项Time to get drinking!（该喝水了！）是适合的文章标题

【解析】本文是一篇议论文。文章讨论了人体水分对人体健康和运动的影响。

1.细节理解题。根据第一段“However，a loss of only two percent of this water through dehydration(脱水)during exercise can significantly affect your performance.”可知，在运动过程中失去百分之二的水分，运动表现就会受到显著影响。故选B。

2.细节理解题。根据第三段“When we exercise，on the other hand，our thirst mechanism(结构) does not work as effectively，so we don't notice early enough that we are actually thirsty. ”可知，由于体内口渴机制的滞后性，运动的时候不太容易意识到口渴。故选C。

3.细节理解题。根据最后一段“You also need to match your intake to the sort of exercise you are doing.”可知，根据运动量设置饮用水量。故选B。

4.主旨大意题。文章讨论了人体水分对人体健康和运动的影响。选项A“保持健康”概念太大，不符合文意；选项B“对运动说再见”不符合文意；以及选项D“避免脱水的方法”概括片面。C项“喝水的时间到了！”作文章题目最适合。

【名师点睛】

主旨大意主要的解题策略有：

（1）标题类。文章标题可以是单词，短语，也可以是句子，它的特点是：短小精悍，多为一短语；涵盖性强，一般要求能覆盖全文，其确定的范围要恰当，既不能太大，也不能太小；精确性强，不能随意改变语言表意的程度及色彩。

（2）主旨类。概括主旨的方法是：先看首尾或各段开头再看全文找主题句，若无明显主题句，就通过关键词句来概括(如议论文中寻找表达作者观点态度的词句，记叙文寻找概括情节和中心的动词或反映人物特点的形容词)。文中出现两种或两种以上的不同观点时，务必牢记作者的观点才是体现全文中心的。此时，要注意一些转折词，如but, yet, however, although, in spite of, by contrast, on the contrary等。当文章中表示相反的观点时，往往用到这些词。答题时要弄清哪个是作者的观点，排除迷惑性信息，准确归纳主旨大意。例如文章的第4小题：

C【解题剖析】此题属于主旨大意中的（1）一一标题类。答案需要理解文章后归纳文章中心。

【推理关系】题干What would be the best title for the text? ☞第一段指出脱水会影响你的运动表现；第二段指出脱水导致的问题；第三、四段讲述我们为什么会失那么多的水；第五段是如何防止脱水。所以文章通篇是讲水的重要性，鼓励人们喝水。