[原创]求解prep语法新题一道prep1-188

snow13

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.

英语很多句子都有意思上的对称，更多是广义上的，先不看具体意思，原文大概是
Neuroscientists  以前怎么样，now现在怎么样，根据now drawing所以句子前部分也应该出现v-ing形式，而画线后说的是now，所以之前应该用过去时态，留AB。

楼上把意思说的很明白，B改变了意思，所以答案A。

greatbusy

这个如何去区分非限制性的having done是可以用的，但是限制性的不能用？

xxxyyyzzz1

同问！请版主解答~

efay

同问having done。。。。

happywawa

同问having done...?

vivian_dong

顶having done的问题。

moonwalker

这题是OG12的21题。

poirotsky

    

This sentence introduces the
subject

            {Neuroscientists), pauses to explain what

neuroscientists have accomplished in the past

twenty years, and then concludes by explaining

what neuroscientists are presently doing as a result

of their past accomplishments. The second part of

the sentence—the explanation—interrupts the

flow of the sentence from the subject

            (Neuroscientists) to the predicate (are now drawing

solid conclusions ...); it should therefore be

bracketed by commas. The sentence construction

should provide a main verb for the subject

            neuroscientists.

    

A    Correct. The explanatory phrase
between

the subject and predicate is set off by

commas, and the main clause contains both

a subject (Neuroscientists) and a

corresponding verb (are now drawing).

    

B    And are indicates that are follows a previous

verb, but in fact the sentence has not yet

provided a first main verb for the subject

            Neuroscientists; the sentence is therefore

incomplete; over the ... years appears to be

modifying adulthood.

    

C    Amassing, like having amassed, functions as

an adjective, not a verb; the sentence

therefore lacks the first main verb implied

by the compound verb construction and are

now drawing....

        

D    The final descriptor in present tense, now

drawing conclusions ... does not fit the

opening clause, which is in present-perfect

tense (have
amassed a wealth ...) and seems

to modify adulthood.

        

E    Like D, this sentence
attempts to attach a

present-tense descriptor to a present-perfect

clause.

        

The correct answer is A.

        

[此贴子已经被作者于2009/9/4 2:24:02编辑过]

verylotus

同问having done    引用aeoluseros斑竹的解释

我对定语、状语的理解是这样的：有的时候同一个成分、结构可以做定语，也可以做状语，只要区分被修饰对象与结合时态等分析逻辑上能不能合理修饰就够了，没必要太在意是做定语还是做状语。也就是说，区不区分定语、状语都可以，关键是要明白定语和状语的功能都是“修饰”(有点像废话，不过我的意思是平时我统一把他们记为“修饰语”，只有在做题目解释的时候才区分一下)。

prep1-188中，A选项"having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood"，你可以把这个成分理解成状语，也可以理解为定语，修饰的都是Neuroscientists这个主体或这个主体发出的动作，只要你把having看做定语和状语时，句意理解起来是一样的，那么就没有歧义问题。

而prep1-97：Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.这里面having可能修饰pollutants，也可能修饰they have introduced some 100,000 dangerous chemical pollutants整个分句，所以having产生了修饰歧义。

 

 

 

个人总结了一下关键看是否会产生歧义，但这个说法有点悬。。个人理解，一般情况下，having done 后置比较容易出问题，既可以修饰就近的名词，又可以修饰主语，还可以修饰整句话，就导致了歧义。。。所以having done若出现在句首，或者在  主语，having done.....,谓语 doing....这种结构中就不能以此作为错误的依据。。。

不知道理解得对不对

我对定语、状语的理解是这样的：有的时候同一个成分、结构可以做定语，也可以做状语，只要区分被修饰对象与结合时态等分析逻辑上能不能合理修饰就够了，没必要太在意是做定语还是做状语。也就是说，区不区分定语、状语都可以，关键是要明白定语和状语的功能都是“修饰”(有点像废话，不过我的意思是平时我统一把他们记为“修饰语”，只有在做题目解释的时候才区分一下)。

prep1-188中，A选项"having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood"，你可以把这个成分理解成状语，也可以理解为定语，修饰的都是Neuroscientists这个主体或这个主体发出的动作，只要你把having看做定语和状语时，句意理解起来是一样的，那么就没有歧义问题。

而prep1-97：Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.这里面having可能修饰pollutants，也可能修饰they have introduced some 100,000 dangerous chemical pollutants整个分句，所以having产生了修饰歧义。

 

 

 

个人总结了一下关键看是否会产生歧义，但这个说法有点悬。。个人理解，一般情况下，having done 后置比较容易出问题，既可以修饰就近的名词，又可以修饰主语，还可以修饰整句话，就导致了歧义。。。所以having done若出现在句首，或者在  主语，having done.....,谓语 doing....这种结构中就不能以此作为错误的依据。。。

不知道理解得对不对

Raymond_GMAT

having done 也对了，看来真的没有必对的技巧，呵呵，逻辑合理，简洁才是GMAC的通理