B不是不对，也有这个可能，但跟C比起来，C明显更好更直接，呼应了题干中的“Maize contains the vitamin niacin, but not in a form the body can absorb”，如果题干中写的是"Maize contains the vitamin niacin, but not in that grown from soil condition of majority of European farmlands",可能B就更好了，个人看法。 -- by 会员 cc621josh (2010/11/25 16:08:26)
3KS 我回头看了看 你不感觉C中没有提到题干中的 European 么？这样很有可能导致C很片面的阐述问题 -- by 会员 larryywddd (2010/11/25 16:30:48)
The point is you need to explain why Americans do not develop Pellagra due to niacin deficiency as Europeans do, even though they all eat Maize, which contains vitamin niacin.
Consider that the vitamin niacin contained in raw Maize is not in form that human body can absorb, there might be some measures taken unconsciously by Americans to convert vitamin niacin from an unabsorbable form to aborbable one. The measure can be cooking method, preparing way, whatever works.
It is just one way to explaination; there is no need to list all possible explainations. In C explaination, European is not necessary here, but might be useful in other exaplainations. | 
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发表于 2010-11-25 15:18:23
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