prep 1-154 有疑问，之前的讨论帖没找到答案。

zhangtao1125

prep 1-154

Some patients who do not respond totherapies for depression may simply have received

inadequate treatment, having, forexample, been prescribed a drug at a dosage too low to be

effective or having been taken off a drugtoo soon.

(A) having, for example, been prescribeda drug at a dosage too low to be effective or having been

(B) having, for example, a drugprescription that was ineffective because the dosage was too low,

or being

(C) as, for example, having too low of adosage of a prescribed drug for it to be effective, or being

(D) when they have, for example, beenprescribed too low a drug dosage to be effective, or were

(E) for example, when they have a drugprescription with a dosage too low to be effective, or been

正确答案为A

两个having been的主语只能是patients，那么从两个having been只能作为伴随状语，而不可能作为定语（having done可以作为非限定性定语修饰名词，但这里不符合题意）。但是前面主句的谓语是完成时态，伴随状语不是不能修饰完成时态的谓语么，给出一个og上的例子。请大家指点。

OG12-21

Neuroscientists, having amassed a wealth of knowledge over the pasttwenty years about the brain and its development from birth to adulthood, are now drawing solidconclusions about how the human brain grows and how babies acquire language.
(A)Neuroscientists, having amassed a wealth of knowledge over the past twentyyears about the brain and its development from birth to adulthood, are
(B)Neuroscientists, having amassed a wealth of knowledge about the brain and itsdevelopment from birth to adulthood over the past twenty years, and are

(C)Neuroscientists amassing a wealth of knowledge about the brain and itsdevelopment from birth to adulthood over the past twenty years, and are
(D)Neuroscientists have amassed a wealth of knowledge over the past twenty yearsabout the brain and its development from birth to adulthood,
(E)Neuroscientists have amassed, over the past twenty years, a wealth of knowledgeabout the brain and its development from birth to adulthood,


正确答案为A
og对D选项的解释：The final descriptor in present tense ,now drawing conclusions....doesnot fit the opening clause, which is in present-prefecttense(have amassed a wealth)and seems to midify adulthood.


如果prep 1-154 的后面两个having done是伴随状语，那么是否可以理解为，主句谓语为完成时态时，后面作伴随状语的分词也用完成时态作为伴随状语就是成立的，而且是否是只能用完成时态呢。根据OG那道题对D选项的解释，发现关键的不是伴随状语不能修饰完成时态的谓语，而是present tense，这个时态上不合适。请大家指点。

balapupu

顶~~记得新东方讲过having been done 必错~~坑爹啊。。

sirenfish

GWD这题的分词结构部分是对主句谓语的补充说明：那些疗效不显著的病人只是还没吃够足够的药罢了，比如（怎么个不够法？）没拿到足够剂量的药，或者过早停药。

如果用having too low of adosage of a prescribed drug for it to be effective, or being，那就无法表现补充说明的关系，不能作为伴随状语放在句子里了。不过这题我觉得做出来是用排除法，BCDE有明显错误，呵呵。

OG的说明不是说伴随状语不能修饰现在往完成时的句子吧，是这个作为状语部分的时态和主句的现在完成时不符。

zhangtao1125

thx那么就是说，主句谓语为完成时，伴随状语要用完成时。主句谓语为其他时态时，伴随状语可以是进行时时态，也可以是完成时时态。可以这么理解么。

myancamel

thx那么就是说，主句谓语为完成时，伴随状语要用完成时。主句谓语为其他时态时，伴随状语可以是进行时时态，也可以是完成时时态。可以这么理解么。

-- by 会员 zhangtao1125 (2011/8/23 20:09:04)

从选项上看，应该不能得到你说的结论，因为其他选项都是其他各类错误，没体现出只能用完成时；只能说用完成时是对的


GMAC在告诉我们，不要找这种having been纠错的规律，给你们出道对的看看，呵呵