OG12上的关于Ing使用的语法题 不懂！求助！

michelle0324

第一题里：The Glass House Mountains in Queensland, Australia, were sighted in 1770 by the english navigator Captain James Cook,__________________ sheer wet rocks glistened like glass.
正确答案是D：who so named them supposedly because their
我选择是正确的 然后OG给出的对于C答案：【naming】 them supposedly since their 的解释是：James Cook does not work as the noun that the verbal phrase beginning with 【naming】 can describe. 所以我认为 "naming " 是describe 句子主语The Glass House Mountains的，而不是紧接着的那个noun

另一道题是21T里面的
(Neuroscientists,having amassed a wealth of knowledge over the past 20 years about the brain and its development from birth to adulthood,are) now drawing solid conclusions about how the ....
括号部分是划线部分，这个也是正确答案
但是同时，在这里的D选项中，Neuroscientists have amassed a wealth of knowledge over the past 20 years about the brain and its development from birth to adulthood, now 【drawing】 solid conclusions about how the ....
这里对drawing的解释是:the final descriptor in present tense, now drawing conclusions....does not fit the opening clause, which is in present-perfect tense and seems to modify adulthood...
说时态不对称那一部分我理解，但是之后又说像是在modify adulthood.....我不理解诶，为什么不是modify 句子主语Neuroscientists，和上面那题目一样？
到底ving是modify紧跟着的noun还是前句子的主语？

sisichen666

亲先看个链接：里面都是og12的解答，有问题再po上来哈：http://forum.chasedream.com/GMAT_SC/thread-763696-1-1.html