单选题 Eight cups of water a day is a longstanding advice. "But is there any scientific basis for it?" asks Dr. Chris. Some ads of drinks also remind us that a small drop in hydration levels can massively affect performance, so we need to keep hydrated by drinking. They seem pretty scientific, don't they? And it's not a hard sale because drinking feels right—you're hot and sweating.
Well earlier this year, scientists in Australia did an experiment that had never been done before. The group wanted to find out what happened to performance after dehydration. So they took a group of players and exercised them until they lost 3% of their body weight in sweat. Then their performance was assessed after rehydration with either nothing, or enough water to bring them back to 2% dehydration or after full rehydration. So far nothing unusual, but the difference between this and other studies was that the players were blind to the water they got. The fluid was given intravenously without letting them know the volume.
This is vital because we all have such an intimate psychological relationship with water consumption. Remarkably, there was no performance difference between those who were fully rehydrated and those who got nothing. This study was part of a growing movement to "drink to thirst" which hopes to persuade athletes not to over hydrate with the potentially fatal consequence of diluting your sodium level.
Perhaps the result shouldn't be so surprising. Humans evolved in doing intense exercise in extreme heat and dryness. We are able to tolerate losses in water relatively well whereas even slight over hydration can be far more from dangerous. In simple terms, being too watery is as bad for you as being too concentrated. There is a well accepted idea that we should drink about eight cups of water per day. We are flooded with positive messages about the healing properties of water and how it will improve everything from our brains to our bowels. And we know that without it we will die in days. It's a short leap of logic to think that if a lack of water is bad for you then hydration must be good. It surely improves your skin, helps you think, reduces your risk of kidney stones and turns your urine a lovely light, champagne color rather than the orange syrup you produce at the end of a long day when you haven't had time to drink.

单选题 What is the purpose of some ads of drinks?

A.To tell us the relationship of hydration and our performance.
B.To remind us the danger of hydration.
C.To reveal a scientific truth.
D.To sell their goods.

单选题 Why the experiment made by sports scientists in Australia is different from others?

A.The subjects of the experiment are players.
B.The performance was assessed after rehydration.
C.The players didn't know how much water they got.
D.The experiment tried to find out what happened to performance after dehydration.

【正确答案】 C

【答案解析】[解析] 细节题。由文章第二段第五、六句“So far nothing unusual, but the difference between this and other studies was that the players were blind to the water they got. The fluid was given intravenously without letting them know the volume.”可知：澳大利亚体育科学家们在实验中采用静脉注射的方式对受试者进行补水，并且受试者对所补充的水分的量一无所知，这与C项内容相符。所以本题的正确答案为C。

单选题 What is the author's attitude towards "eight cups of water a day"?

A.Doubtful.
B.Supporting.
C.Objective.
D.Neutral.

【正确答案】 A

【答案解析】[解析] 态度题。本题问的是作者对于“一天喝八杯水”这一说法的态度。由文章第一段最后两句“They seem pretty scientific, don't they? And it's not a hard sale because drinking feels right—you're hot and sweating.”和第四段第八句“It's a short leap of logic to think that if a lack of water is bad for you then hydration must be good.”可知：作者认为多喝水不一定对身体有益，他对“一天喝八杯水”的说法表示怀疑，这与A项内容相符。所以本题的正确答案为A。

单选题 Which of the following statements is TRUE?

A.The players of the experiment know how much water they got.
B.The result of the experiment isn't surprising at all.
C.The experiment had once been done before.
D.Being too watery can be harmful to your health.

【正确答案】 D

【答案解析】[解析] 细节题。本题可采用排除法解题。第二段第五、六句“...the players were blind to the water they got. The fluid was given intravenously without letting them know the volume.”与A项内容不符；第四段第一句“Perhaps the result shouldn't be so surprising.”与B项内容不符；第二段第一句“...an experiment that had never been done before.”与C项内容不符。另外文章第四段第四句“In simple terms, being too watery is as bad for you as being too concentrated.”正好符合D项内容。所以本题的正确答案为D。