[求助]平行结构中BE动词的省略问题？(以新PREP228题(GWD-5-Q1)为例)

在平行结构中，如果两个BE动词单复数不同（一个is 一个are），那么第二个BE动词能省略么?

以新PREP228题(GWD-5-Q1)为例

So dogged were Frances Perkins' investigations of the garment industry, and her lobbying for wage and hour reform was persistent, Alfred E. Smith and Franklin D. Roosevelt recruited Perkins to work within the government, rather than as a social worker.

A. and her lobbying for wage and hour reform was persistent,

B. and lobbying for wage and hour reform was persistent, so that

C. her lobbying for wage and hour reform persistent, that

D. lobbying for wage and hour reform was so persistent,

E. so persistent her lobbying for wage and hour reform, that

答案是E

很想不通的地方在于， 这里貌似少了一个and 省略的BE动词也不一样，第一个分句是were 第二个是was

把句子还原回来是这样吗？

两个BE动词不一样啊。。。 而且中间也还少 and...

以新PREP228题(GWD-5-Q1)为例

So dogged were Frances Perkins' investigations of the garment industry, and her lobbying for wage and hour reform was persistent, Alfred E. Smith and Franklin D. Roosevelt recruited Perkins to work within the government, rather than as a social worker.

A. and her lobbying for wage and hour reform was persistent,

B. and lobbying for wage and hour reform was persistent, so that

C. her lobbying for wage and hour reform persistent, that

D. lobbying for wage and hour reform was so persistent,

E. so persistent her lobbying for wage and hour reform, that

答案是D

很想不通的地方在于， 这里貌似少了一个and 省略的BE动词也不一样，第一个分句是were 第二个是was

看到种解释好想是说有

so ... were ..., so ...(were)..., that ...

的句型

不解，有NN能回答下吗？

那后半句在句子中的成分是什么呢？是并列关系么， 到底起什么作用呀~谢谢：）