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）

(E) determined by when the sun reached the observer’s meridian and differing

我认为应该选C。为什么选E呢？

In choice A, was is incorrect; the verb must be were to agree with times. Also, which becomes the subject of a compound verb that lacks parallelism: was determined…and differing. In choice B, was is again incorrect, and the use of two which clauses is awkward. In choice C, which were determined…and differing is another faulty compound verb. Choice D presents a false compound: determined is an adjective modifying local times and differed is the simple past tense of to differ. Because they serve different grammatical functions, these words cannot be treated as parallel elements joined by and. Choice E is best: without which, determined and differing function not as verb elements but as parallel modifiers of local times. This question is very difficult.

B：1、其中的两个which同指一物；

2、由which was 知其指的是the abolition 而非the local times.

3、而determined 和differ都是指local times的。

把B中的was 改为were也不如E好(时态，不简洁)。