你每天需要喝8杯水吗？

　　Do you need eight glasses of water everyday?

       Tring to do the right thing by drinking eight full glasses of water everyday may do little more than making a person run to the bathroom, a researcher said. Newspaper articles, health and beauty magazines all advise drinking at least eight full glasses of water a day, totalling 64 ounces for optimal¹ health. And the approach called "8 x 8" by proponent².
But doctor Heinz Valtin, a Dartmouth medical school in New Hampshire said "there is no scientific evidence to back up the advice which help create huge market for bottled water". "After ten month of careful searching, I have found no scrientific evidence that support 8 x 8", Valtin, a kidney specialist who is in textbooks on the subjects of human water balance, said in a telephone interview. Writing in the American Journal of Physiology³, Walton said that people forget that the food they eat also contains some water.
I did 46 years of research on that system--the osmoregulatory system. That system is so precise and so fast that I find impossible to believe. The evolution left us with a chronic⁴ water deficit⁵, Valtin said. If a person gets low on fluid, the body compensates⁶ by bringing fluid back out of the kidneys and by slowing the lots of water through the skin, Valtin said. Thus takes in long before the dehydration⁷ starts, he added.

1 optimal   

adj.最适宜的；最理想的；最令人满意的

参考例句：

• What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么？
• Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。

2 proponent   

n.建议者；支持者；adj.建议的

参考例句：

• Stapp became a strong early proponent of automobile seat belts.斯塔普是力主在汽车上采用座椅安全带的早期倡导者。
• Halsey was identified as a leading proponent of the values of progressive education.哈尔西被认为是进步教育价值观的主要支持者。

3 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

4 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

5 deficit   

n.亏空，亏损；赤字，逆差

参考例句：

• The directors have reported a deficit of 2.5 million dollars.董事们报告赤字为250万美元。
• We have a great deficit this year.我们今年有很大亏损。

6 compensates   

补偿，报酬( compensate的第三人称单数 )； 给（某人）赔偿（或赔款）

参考例句：

• The company compensates her for extra work. 公司因她的额外工作而给她报酬。
• A vertical spring compensates for the weight of the sensing element. 用一根垂直弹簧补偿敏感元件的负荷。

7 dehydration   

n.脱水，干燥

参考例句：

• He died from severe dehydration.他死于严重脱水。
• The eyes are often retracted from dehydration.眼睛常因脱水而凹陷。