prep 1-130 对prep笔记的解释有疑问，请大家看看。

zhangtao1125

请大家先看这道题：

prep 1-28

Polio, although it is eradicated in theUnited States, it continues elsewhere and is able to be

brought into the country by visitors.

(A) Polio, although it is eradicated inthe United States, it continues elsewhere and is able to be

(B) Polio, although eradicated in theUnited States, it still continues elsewhere and can be

(C) Although still continuing elsewhere,polio has been eradicated in the United States and

could be

(D) Although having been eradicated inthe United States, polio still continues elsewhere and is

capable of being

(E) Although eradicated in the UnitedStates, polio continues elsewhere and could be  

prep对D选项的错误的解释为现在分词的完成时态不能作为定语修饰名词，不论是前置定语还是后置定语，所以D选项错误了。

再看prep 1-130

Industrialization and modern methods ofinsect control have improved the standard of living around

the globe while at the same time theyhave introduced some 100,000 dangerous chemical

pollutants, having gone virtuallyunregulated since they were developed more than 50 years ago.

(A) while at the same time they haveintroduced some 100,000 dangerous chemical pollutants,

having

(B) while at the same time introducingsome 100,000 dangerous chemical pollutants that have

(C) whilethey have introduced some 100,000 dangerous chemical pollutants at the sametime, and

have

(D) but introducing some 100,000dangerous chemical pollutants at the same time that have

(E) but at the same time introduce some100,000 dangerous chemical pollutants, having

如果现在分词的完成形式不能作为定语修饰名词，那么AE两项中的 having gone....就只能作为伴随状语，其主语应该为 industrialization and modern methods。而这不和逻辑，所以错误。（这里我不同意prep上面的解释，我不认为有可能作后置定语，又可能作伴随状语的歧义，请大家指正。）

athue

188.    (26379-!-item-!-188;#058&001961)

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,

顶楼主。我对having done的用法也很模糊，这是prep08 sc1的188题，也是0g12-21，这里A选项中的having amassed 到底是状语还是做定语修饰呢？如果是做状语，那么怎么知道A没有做定语向前修饰的歧义？另外除了改重心的问题，DE选项有硬伤没有？笔记上说现在分词的完成形式不能修饰现在完成时，这个有例证没？

athue

坐等，求指点~~~

AlohaDJ

having done能作句子的状语，不能作后置定语修饰名词。
这么记就行了。

athue

请问，那我怎么知道这里是状语还是后置定语呢，如OG12-21？

AlohaDJ

请问，那我怎么知道这里是状语还是后置定语呢，如OG12-21？

-- by 会员 athue (2011/8/22 22:25:30)

由句子的逻辑意思判断！hm..这么说可能会觉得抽象哈，不过我自己就是这么做的。。

看到noun+having done（这是having done作后置定语的情形），马上杀！

至于having done做状语的情形，有时在句首，有时在句中（一般前后用逗号隔开）。
拿OG12-21这题举例：其实having done结构也可以放在句首做句子的状语，表示和主句的时间先后。

AlohaDJ

OG12-21, 我觉得是对'逗号+ing'做结果状语的反向考法。

D中的now drawing在主句后面，按逻辑意思应该是结果状语(因为有时间先后,排除伴随状语)，表示前面整句话发生后的结果，这样的结果状语是没有'明确的'逻辑主语的（尽管是前面整句话造成的结果）。换言之，如果前面主句中的主语（如这句中的Neuroscientists）能做结果状语的主语，那就说明句子结构是错的，后面这部分（now drawing）就本不能是结果状语，需选项A那样安排句子结构。

zhangtao1125

prep 1-28 D选项那样的前置定语算是非限定性定语，用逗号隔开的后置定语也算是非限定性定语，只有紧跟在名词后面的后置定语才算是限定性定语，这么理解对么。根据版主aeoluseros的补充，having done可以作为非限定性的定语，表示的内容在主句动作之前。

那么prep 1-28 D选项的having done可以作为定语修饰polio了，而且eradicate这个动作在后面主句动作之前，这从逻辑上也没有问题，那么这里是不是although having been eradicated和although eradicated 都是正确的呢，不考虑后面的错误的情况下。