prep2-32

yidiyuehan

我觉得B为什么不用过去完成时应该是加入了originally， 更适合用一般过去时，至于by doing 的主语一般是施动者大部分时候合乎逻辑，不过我觉得象楼上举例PREP99 就是例外，还真不能靠这个排除:

prep2

99. (29685-!-item-!-188;#058&004361)

Frederick Winslow Taylor, a machinist and engineer who worked in the early twentieth century,

believed that the productivity of a job could be improved if one were to separate the components of

a task into its individual motions and found the best way to perform each motion, then redesign the

job so that each motion could be done as efficiently as possible.      

(A) if one were to separate the components of a task into its individual motions and found the best

way to perform each motion, then redesign

(B) if one separated the components of a task into individual motions, found the best way to perform

the motions, and then redesigning

(C) if the components of a task were separated into individual motions, finding the best way of

performing the motions, and then redesigned

(D) by separating the components of a task into individual motions, finding the best way to perform

each motion, and then redesigning

(E) by separating the components of a task into individual motions, finding the best way of

performing each motion, then redesign

onedayling

 

看了帖子明白了by的用法。那我想请问 A.  中的  but having being这个用法可以吗？即but后可以跟分词修饰主语吗？

[此贴子已经被作者于2009/9/30 1:06:39编辑过]

Bourne_NY

prep2 - 99这题吧，

ABCE都有明显错误，而D怎么看怎么顺眼，by doing表方式方法，多好的结构啊，干嘛不选。有时不必太拘泥于这个结构是否与句子主语在逻辑上一致，尤其是被动式的句子里。

Bourne_NY

GMAT里but一般都作连词，而它作介词时意思是除了，在芝加哥河这句里意思不对。

[此贴子已经被作者于2009/9/30 2:11:46编辑过]

Raymond_GMAT

E把原来的限制性定于从句改成了非限制性定于从句没有问题么？

制约与平衡

关于使用过去完成时和过去时的问题：
过去时用来表示过去时（现在不是了），比如：He was a good guy. 他以前是个好人。可能变坏了，也可能是死了（不是开玩笑。）
楼主的题中说the river flowed真是说明现在不是，以前是。所以E选项中用到了flowing。
19楼的这个题说的是要表现出和人们现在的realize对比。
OG上说过去完成时用来表现两个发生在过去的时间的先后顺序。现在完成时用在形容一个发生在过去但不知道确切时间的事件或者过去开始一直延续到现在的事件。无论如何都是过去开始的事件。那么用过去完成时正是表现出了这两个时间的顺序，其发生在现在完成时的这个事件之前。

yunshishow

顶起来

812966141

manhattan的讲解：there are two things wrong with (b).

one:
the use of the past perfect (had flowed) is inappropriate, because there is no second past-time marker or event to which this first event is relevant.
compare: the rivers had originally flowed into the st. lawrence, but then their course was diverted by...
the correct tense to use here would be the simple past, because this is the only past time frame referenced in the whole sentence.

two:
'by constructing' seems to refer back to the rivers as its ostensible subject, implying (absurdly) that the rivers themselves constructed the canals.

812966141

我排除E的原因是因为，flowing多表示现在。而这个指过去，我觉着不太好。求高手解答flowing，现在分词子此处的用法

zwhjzwhj

我当时看到这个flowing的修饰就没选，反正翻来覆去怎么说都是他们有理，不让用ving修饰的时候就说，这是强调动作正在进行，自己用的时候就不管了。