OG 13老题新问，关于逗号的使用

proteller

OG 13 SC 25题目如下
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,

这道题答案是A，自己当初也做对了，对于OG解析上的E选项的错误之处也能理解。现在的困惑是这个E选项里面的“comma逗号”是否“违和感”过强呢？我的理解是E选项中间over the past twenty years前面的逗号是错误的，按照Manhattan语法上的说法，似乎是“non-essential”修饰语要拿逗号隔开而“essential”修饰语则不能拿逗号隔开，这里面我感觉over the past twenty years应该算是“essential”修饰语，所以我觉得就逗号而言，E选项也有一定的问题......不知道各位CDer怎么看？

longee

很少考标点的，当插入语来做，意思对就行。

proteller

longee 发表于 2013-4-7 12:58
很少考标点的，当插入语来做，意思对就行。

这不是想尽量弄明白嘛

longee

proteller 发表于 2013-4-7 13:00
这不是想尽量弄明白嘛

好吧，这么用的其实挺多的，我觉得没什么错。如果都对，你就看哪个简练吧

kiwifoodtown

不认为E选项的over the past twenty years有什么问题，E的主要问题就是状语升格，主句降格。

proteller

kiwifoodtown 发表于 2013-4-7 13:04
不认为E选项的over the past twenty years有什么问题，E的主要问题就是状语升格，主句降格。 ...

我明白E错在何处，只是觉得over the past twenty years前面的逗号也似乎不大好......