OG12 SC 86 求解

jj0615

after falling是状语从句省略，还原的话不是after it  fell over the last two years么........

stella1220

OG里面说 “The sentence therefore needs to clarify the sequence by presenting the first-identified indicator in a clause with a verb tense that indicates a later time period than the verb tense in the clause presenting the second-identified indicator.” 按照我的理解，也就意味着句子中的have increased (first-identified indicator) 的时态要能体现出其发生在falling (second-identified indicator) 之后。

我不解的是这个after falling 到底算什么结构？哪个NN来给解释一下，还原一下省略部分？难道是had been falling?

stella1220

俄，刚刚查了一下语法书，after falling的确是状语从句，但是不能算是省略（个人觉得）。《新编英语语法》1204页上写：
当before和after引导-ing分词分句时是介词，转换成限定分句时才是连词。例如：
Before entering the nozzle (喷嘴), the stream is at high pressure.
= Before it enters the nozzle, the steam is at high pressure.

After leaving the blades, the steam passes out to the atmosphere.
=After it leaves the blades, the steam passes out to the atomosphere.

赤尾屿

俄，刚刚查了一下语法书，after falling的确是状语从句，但是不能算是省略（个人觉得）。《新编英语语法》1204页上写：
当before和after引导-ing分词分句时是介词，转换成限定分句时才是连词。例如：
Before entering the nozzle (喷嘴), the stream is at high pressure.
= Before it enters the nozzle, the steam is at high pressure.

After leaving the blades, the steam passes out to the atmosphere.
=After it leaves the blades, the steam passes out to the atomosphere.

-- by 会员 stella1220 (2012/6/6 2:36:35)

有道理，这里的before不能算作状语从句的省略，只能当作一个普通的介词。如果当作状语从句省略，和之前所有的状从省略，省略动词必为be就有定矛盾了。
懂了懂了，非常谢谢拉~~~

zoeyun2012

falling有点类似于财经文章的习惯用法。
将falling看做名词好了！

小迪大战GMAT

那这里的after falling是怎么与原句的have increased在时态上区分开的呢？