piloteer的白勇题目-11题

11．The growth of the railroads led to the abolition of local times, which was determined by when the sun reached the observer's meridian and differing from city to city, and to the establishment of regional times.
（A）which was determined by when the sun reached the observer's meridian and differing
（B）which was determined by when the sun reached the observer's meridian and which differed
（C）which were determined by when the sun reached the observer's meridian and differing
（D）determined by when the sun reached the observer's meridian and differed
（E）determined by when the sun reached the observer's meridian and differing

答案是E, 前后led to....and to是个平行结构，然后中间的修饰成分还有个平行结构。用Local times的复数排除了A,B, 还似乎可以用C的平行结构前后语态的不同排除C。最后剩下来的D，似乎可以用differ的逻辑上用被动语态有问题来排除。

但是，如果E是正确的话，这是一个什么结构呢？是过去分词短语和现在分词短语的平行结构修饰前面的名词吗？但是如果这样的话，这两个分词短语结构前后是有逗号的，分词短语可以用逗号隔开地形容前面的词语吗？

非常不解，求NN解答！

determined by when the sun reached the observer's meridian and differing相当于which were determined by when the sun reached the observer's meridian and differ吧