OG13-SC-25 现在分词作状语修饰的时态问题，请NN解答，谢谢啦！

airyun

Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.

(A) Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are
(B) Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(C) Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(D) Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood,
(E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood.
虽然当时选对了，但是我在回顾的时候发现D选项OG的解释让我有点困惑，OG解释说这里的 now drawing 和主句的 have amassed现在完成时态不能匹配，而且看起来是在修饰 adulthood。。。commas+v-ing在句尾不是首要考虑做主句动作的状语修饰吗？这里怎么会看起来在修饰drawing? 现在分词在句尾做状语修饰的时候不是时态来自于主句动作么？这里为什么又说和主句的现在完成时态不一致？之前在一个讲语法的博客里看到过一个解释：commas+v-ing在句尾时，如果时态和主句时态一致，那么就是做状语修饰，如果时态不一致，那么是做定语修饰最紧挨着的名词，请问NN这个说法有根据吗？如果是正确的，那么遇到问题时该怎么判断现在分词的时态？
这道题我也看了千行的解释，里面说now是个判断drawing是不是结果状语修饰的关键，now暗示了过去和现在状况的对比，我不敢苟同，因为now也可以说过去的情况到现在更加稳固或者怎么怎么样正向发展了，而且作为直接have amassed a wealth of knowledge的直接结果，draw a solid conclusion做结果状语我觉得也是可以的呀。。。
请大牛指教哇！！！在这里多谢啦！

airyun

忘了说。。。答案是A哈~

airyun

哇，我没有看，为啥这个标题前面是悬赏令了？？是不是需要重新发一下？还是可以改掉啊？

skyemotion

now drawing solid conclusions about how the human brain grows and how babies acquire language.
now是一个决定性的词语，标示了conclusions 和之前的认知过程不是一个伴随关系。

suapplle

同问，帮顶~
我当时做的时候没有想到这一点，直接选了A，果然还是不太懂……

yy20

因为amass这个动作发生在过去，而在D答案里now drawing是一个现在时的modifier，所以时态不当。而且原句里作者强调neuroscientists are now drawing blablabla...having amassed 只是一个modifier，D答案改变了句子中心，把amass作为了main verb,而drawing变成了modifier，错了。

yy20

关于那个Ving的修饰，千行上面说Og解释有误啊。。。这是千行的解释你看看~
ron的解释：D,E选项没有歧义，只能modify主句的成分 ，不能modify adulthood
comma+participle
this sort of modifier should actually satisfy TWO requirements:

1) it should apply most nearly to the subject of the preceding clause (as you've said); and, even more importantly,

2) it should have one of the following RELATIONSHIPS to that clause:

* immediate consequence
* simultaneous, but lower-priority, action

here, this modifier doesn't have either of these 2 relationships to the main clause, so it's used inappropriately.