but - 完全平行的标志？

看到很多sc总结上都说but是平行的标志，遂坚信不疑。今天做prep就因此碰壁了～ 且看此题：

Unlike many United States cities, where a river is no longer the focal point of urban life, the river in San Antonio winds through the middle of the business district, and the River Walk, or Paseo del Rio, is the city's most popular attraction.

(A) Unlike many United States cities, where a river is no longer the focal point of urban life, the river in San Antonio

(B) Unlike the river in many cities in the United States, which is no longer the focal point of urban life, in San Antonio the river

(C) Today the river in many cities in the United States is no longer the focal point of urban life, unlike San Antonio, where it

(D) In few United States cities today, a river is the focal point of urban life, but the river in San Antonio

(E) No longer do many cities in the United States have a river as the focal point of urban life, but in San Antonio the river 

上来一看unlike, 心想小样又考平行啊！啪啪啪把A(cities-river),C(river-San Antonio),E(完全不平行啊！)给排除了，在一看B选项which修饰有问题，最后选了D。 回头对了答案看了笔记方知，but连接并列分句并不需要形式上的完全对等！！！

这段时间做题感受最深就是语法点判断固然重要，但是对句意的整体把握（逻辑性）现在好像更加的重要了！还有不到一个月就要考了，感觉水平还很差，现在好紧张啊～

补充：

rather than, but, and等词更重要的是要对比各选项之间并列成分的区别是否保持了原句要表达的意思。（也就是看原句合理的逻辑意思有没有被破坏）

恩，知识点掌握不充分！

原来我以为并列分句成分也需要平行的