GWD-18-Q2求教，已搜索无结果，谢谢大家了！

GWD-18-Q2:A?
According to findings derived from functional magnetic resonance imaging (MRI), the area of the brain in which a second or third language is stored depends on the age of the language learner; whereas each language occupies a distinct area of the brain in an adult learner, language areas overlap in a young child.

A.    whereas each language occupies a distinct area of the brain in an adult learner,
B.    whereas for adults each language occupies a distinct area of the brain and whereas是连词, 再用and错误.
C.    each language occupies a distinct area of the brain when they are learned by an adult这个很罗嗦,而且they指代不明, while
D.    each language in adults occupied 过去式不对 a distinct area of the brain, while
E.    each language occupying时态不对 a distinct area of the brain for an adult learner, and
whereas表达不对 的具体用法有哪些？谢谢了，一遇到就会晕

关于whereas的还有这道题，不过貌似此题出题点不在whereas和although的区别上，希望好心人说说区别
GWD17-Q14:B?
Whereas lines of competition are clearly defined in the more established industries, in the Internet industry they are blurred and indistinct, as companies that compete one day may be partners the next.

A.    Whereas lines of competition are clearly defined in the 这个the感觉有点怪, 不需要 more established industries, in the Internet industry they are blurred and indistinct, as companies that compete 没有说清楚竞争什么?
B.    Although the lines of competition are clearly defined in industries that are more established, they are blurred and indistinct in the Internet industry, as competing companies 意思是: 曾经竞争过的公司blabla....
C.    The lines of competition are clearly defined in the more established industries, unlike the Internet 对比错误 where 错误 they are blurred and indistinct, as companies that compete
D.    Unlike more established industries, where GMAT中大部分用where都不对, 应该用in which the lines of competition are clearly defined, they前面复杂的句式让这个指代不明, 不知道是industries还是lines are burred and indistinct in the Internet industry, as companies that compete
E.    Unlike more established industries前后对比的主体不对, with clearly defined lines of competition, those 指代不明,错 of the Internet industry are blurred and indistinct, as competing companies
答案是B

请教各位NN， 为什么B选项不对？
language areas overlap in a young child  这句话是个独立的句子吗？
如果选A的话whereas each language occupies a distinct area of the brain in an adult learner, language areas overlap in a young child. 这里逗号连接了2个句子，不是错了吗？
B选项加了and就解决了这个问题？急求解，谢谢！！！
这个句子该怎么翻译呢？

关于whereas的还有这道题，不过貌似此题出题点不在whereas和although的区别上，希望好心人说说区别
GWD17-Q14:B?
Whereas lines of competition are clearly defined in the more established industries, in the Internet industry they are blurred and indistinct, as companies that compete one day may be partners the next.

A.    Whereas lines of competition are clearly defined in the more established industries, in the Internet industry they are blurred and indistinct, as companies that compete
B.    Although the lines of competition are clearly defined in industries that are more established, they are blurred and indistinct in the Internet industry, as competing companies
C.    The lines of competition are clearly defined in the more established industries, unlike the Internet where they are blurred and indistinct, as companies that compete
D.    Unlike more established industries, where the lines of competition are clearly defined, they are burred and indistinct in the Internet industry, as companies that compete
E.    Unlike more established industries, with clearly defined lines of competition, those of the Internet industry are blurred and indistinct, as competing companies
答案是B