whereas in mammals me tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes form a random pattern.
(A) Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes
(B) Whereas the tiny tubes for the conveying of nutrients to bone cells are arrayed in mammals in parallel lines, birds have tubes that
(C) Unlike mammals, where the tiny tubes for conveying nutrients to bone cells are arrayed in parallel lines, birds' tubes
(D) Unlike mammals, in whom the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, the tubes in birds
(E) Unlike the tiny tubes that convey nutrients to bone cells, which in mammals are arrayed in parallel lines, in birds the tubes
题目分析：句子逗号前后就是一个对比，A的感觉是在一个地，tiny tubes怎么样了，再另外一个地，这个tubes又怎么样了，比较并列，留着。B前面先说tubes后面说birds不并列。C用mammals和后面的bird’s tubes进行比较，干掉。D和C错误类似，E前面说unlike tiny tubes，后面应该用一个tubes和前面对应，但是后面说的是in birds，干掉。选A。
