问OG12 134 状从省略

zhongshanlh

http://www.manhattangmat.com/forums/industrialization-and-modtern-methods-of-insect-control-have-t460.html?sid=fc19f1cdaac87670468ce1d9120d8fb7
for reference,baby姐姐给过的一个连接，虽然和这个题目没太大关系

marseill

manhattan上的例句:
A new CEO has been hired who will transform the company by decentralizing authority to various division heads while increasing their accountability through the use of public scorecards.
查了查词典, while在这里应该是做介词; 但意思不太确定, 有的词典说有:当...的时候的意思, 也有说只有:直到的意思. 我觉得这里用这两个意思理解都没逻辑错误. 需要跳出while只表示:同时或尽管这两个意思的限制.
Recently implemented“shift-work equations”based on studies of the human sleep cycle havereduced sickness, sleeping on the job, and fatigue among shift workers while raising production efficiency in various industries.

marseill

但是og上说the phrase while raising provides a clear contrast with have reduced.
如果是比较, 那就又是连词了, 依然无解.

marseill

貌似我想多了, 楼主也说第二点，状语从句中的working verb一定是be动词，但不要求主句的working verb也是be动词。
那状语从句就是省略的be动词啊, equations have been raising啊. have也是助动词, 当然也可以省略了.
省略完全没问题

showy

我觉得就是个连词后面跟V-ING  表同时   大家别想太多。  对么？ 请教。

hzasian

这题主要是理解while的用法。While, although, if等等都是subordinate construction，在本句中起连接作用，同时raising production efficiency是studies的谓语，其用法就是常见的comma+ Ving,表示同一主语的两个动作几乎同时发生或者前后有一定的因果联系。但是coordinating conjunction 如but, and, yet就不能这样用。另外，部分subordinate construction不仅可以跟从句，还可以跟adjective或者adjective phrase, 如：James, although bigger than many of the other players, is one of the fastest men on the team。而从本句可以得出，while不仅可以跟ing participle,也可以像although一样跟adjective或者adjective phrase。所以subordinate construction的用法并不只有一条简单的规则。另外一个SC的例子：Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time introducing some 100,000 dangerous chemical pollutants that have gone virtually unregulated since they were developed more than 50 years ago.

avawang

状语从句的省略，不需要从句的谓语动词是be。
我第一次做这道题也困惑了很长时间，gmatclub,beat gmat上看了半天还是觉得混乱，来CD论坛查了半天NN们的解释。贴下自己的见解，供以后的同学们参考。

状语从句的省略，当从句主语和主句主语相同时，可以把状语从句变成短句。
(1)从句还有be动词，把从句的主语和be动词省略
eg. When (he was) a student in the university, he read a lot.
(2)从句没有be 动词，从句主语省略，动词变为doing形式。

语法解释来源：《英语语法新思维高级教程》（这是08语法笔记前言部分推荐的语法书，前辈NN的推荐，果然很不错）