求教GWD-21-33单个的BF???

娜娜仁

支持e 哦

娜娜仁

天　　打错了　是B

娜娜仁

我认为BF和B相同的作用在于从不同的角度说明水是没用的　　并不一定要和氧的吸收途径联系起来吧　　这样理解对吗？？

gonghao

B is always the answer.

Content following "since" plays a role of support the conclusion that Such water would be useless in improving physical performance.B is saying that since there is enough oxygen in the blood ,such water would be useless.B plays the same role the boldface acts in this question.

C is ok except B is not exist.But we can not say that since small part of us ,world -class athletes, for example,could turn in the records that will get into appearance due to the water.Maybe some other person will get profit from such water since they are not world-class any more.

B is quite good ,it elminated all the disadvatanges appeared in choice C.B is more covered .So B is the answer.

harriethan

E 为什么不对呀~

mymengming

这帮老外认为A是对的
http://www.pagalguy.com/forum/gmat-and-related-discussions/20700-gmat-critical-reasoning-discussions-46.html
理由机器滑稽

rachelchen52

看了各位牛人的解释，

说说我的理解

本题结论是说: 这个推销的水没用，因为通过肺来的氧才能进入血流从而被肌肉吸收.

答案的关键貌似是要强调这个推销的水对肌肉补氧根本起不到一点作用，

1. the water lost in exercising can be replaced with ordinary tap water （这个跑题太远了）
2. the amount of oxygen in the blood of people who are exercising is already more than the muscle cells can absorb（肌肉里的氧份已经饱和了，喝再多那种推销的水，也不可能让肌肉吸收氧，体现了这种水根本起不到任何作用的效果）
3. world-class athletes turn in record performances without such water （这个也跑题太远了）
4. frequent physical exercise increases the body’s ability to take in and use oxygen （这个并不能排除水起不到作用，正因为运动增强吸收、利用氧气的作用，那喝这个水补氧不是正好有利嘛~）
5. lack of oxygen is not the only factor limiting human physical performance（除了缺氧外还有其他制约体力表现的因素，没错，但这还是在说缺氧不好，那推销的水说不定就能帮助补氧，这个选项并不能排除推销的水对补氧有作用的可能性。）

不知道对否，大家讨论~

won872

Context: One of the limiting factors in human physical performance is the amount of oxygen that is absorbed by the muscles from the bloodstream.

Consideration:
            the only way to get oxygen into the bloodstream so that it can be absorbed by the muscles is through the lungs.

Conclusion: water would be useless in improving physical performance

Boldface is a consideration provide in support of the conclusion of the paragraph

“the amount of oxygen in the blood of people who are exercising is already more than the muscle cells can absorb” is another consideration explain why the blood stream can not intake more oxygen. This consideration strengths the conclusion from the same perspective, physical mechanism, which lies within the context of this argument, as the prior consideration.

C: “world-class athletes turn in record performances without such water” is a different issue---stamina---not the physical mechanism of body. Even if the oxygen bottle drink were proved helpful of its physical function to human body, the word class aathlete can still win championship without such water. Does such evidence shows that the water in useless to human body? The bottom line is that the stamina issue has nothing to do with the physical mechanism of body, neither does it affect the usefulness of the drink

xiaoniuren

DD