OG12 P.694 SC 21

176568418

21. 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)

B) Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over 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,

答案：A

問題：
兩個逗號中間的部分應該是定語吧？ 是對前面 neuroscientists的補充說明麼？這個應該怎麼分類？非限制性定語從句？可是為什麼沒有 who啊？逗號中間的句子，謂語在哪裡？
謝謝！

176568418

謝謝你謝謝你再次謝謝你。
發現自己初中英語沒有學好。。。囧。。。
基本的東西得回頭看看。。。

bdsjb116

是我是我还是我

21. 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.

有个小trick 这题划线部分后面是一个now drawing，由于分词ing形式主要是充当伴随结果状语和伴随动作状语，在题目中drawing引出这段话跟前面不存在伴随结果或者伴随动作的关系，因此可以确定此句的谓语为“are now drawing” 因此前面两个逗号直接都是可以省略的插入成分，句子主体为"Neuroscientists are now drawing"

于是判断
第一步：b和c中 and are 明显and多余 排除
第二步：D选项没有谓语 排除
第三部：e中有两个谓语“have amassed” 和“drawing” 排除 且已经改变了原句意思

所以选A