非常典型的一题，学习了。
个人分析是这样的：
先看整体句子结构：led to the abolition of 与 and to the establishment of 构成平行，然后再看划线部分。
determined与differing问题：
划线部分都是用来修饰local times的。
时间被决定（ by when the sun reached the observer's meridian ），故determined用过去分词形式；
时间自己不同（from city to city），故用现在分词。
此题将过去分词与现在分词放一起构成平行，故意增加难度迷惑考生了。
个人判断用过去分词还是现在分词一般是依据动词与其修饰的逻辑主语之间是什么关系。是被动，则过去分词；是主动，则现在分词。
个人看法。
-- by 会员 dzxu (2011/6/27 0:04:30)
3。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.同题中
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
解释：
Choice D presents a false compound: determined is an adjective modifying local times and differed is the simple past tense ofto differ.（不平行） Because they serve different grammatical functions, these words cannot be treated as parallel elements joined byand。
我的问题是：我可以理解为 D 中的 determined 和 differed 都是过去分词表被动，一起来修饰local times 啊，为什么不对呢？总觉得differing 不对啊，differ 不是总是用被动语态吗？
求点拨啊！ 谢谢啦！！-- by 会员 jameshzd (2011/6/25 22:55:47)
~关于C 选项我有两个想法，大家来看看对不对：c.which were determined by when the sun reached the observer's meridian and differing， 个人觉得它错在两点：
~~相信你的
看到lz的精益求精，我收到振奋了= =虽然我时间不多了