In humans, ingested protein is broken down into amino acids, all of which must compete to enter the brain. Subsequent ingestion of sugars leads to the production of insulin, a hormone that breaks down the sugars and also rids the bloodstream of residual amino acids, except for tryptophan. Tryptophan then slips into the brain uncontested and is transformed into the chemical serotonin, increasing the brain’s serotonin level. Thus sugars cause mood elevation, helping one to feel relaxed and anxiety-free. Which one of the following is an assumption on which the argument depends?
(A) Elevation of mood and freedom from anxiety require increasing the level of serotonin the brain. (B) Failure to consume foods rich in sugars results in anxiety and a lowering of mood. (C) Serotonin can be produced naturally only if tryptophan is presented in the bloodstream. (D) Increasing the level of serotonin in the brain promotes relaxation and freedom from anxiety. (E) The consumption of protein-rich foods results in anxiety and a lowering of mood. 这道题看后知道要补GAP,但是A和D的区别是什么呢？ BIBLE对A的解释说：the raising S is sufficient to elevate mood, this answer claims that it is necessary. 假设不就是必要条件吗？为什么这里假设成充分了？
我是这么理解required的：A require B就是A发生了的话，那么B肯定发生了，B是必要条件。 而D中是level of secrotonin的增长（可以）促进放松什么的，没说要放松就一定会发生LOS的增长：有可能LOA或者LOB或者LOC的增长也能促进 ie，require这个词是关键 open to discuss~
我是这么理解required的：A require B就是A发生了的话，那么B肯定发生了，B是必要条件。 而D中是level of secrotonin的增长（可以）促进放松什么的，没说要放松就一定会发生LOS的增长：有可能LOA或者LOB或者LOC的增长也能促进 ie，require这个词是关键 open to discuss~
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发表于 2012-8-25 16:58:58
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