Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than it was in any previous election.
A.a greater proportion than it was
B.a greater proportion than
C.a greater proportion than they have been
h is greater than was so
h is greater than it has been
这道题为什么B是对的啊?
句子分析：
Soaring television costs accounted for … half the spending in the presidential campaign of 1992, a greater proportion than in any previous election.
Soaring television costs主语，accounted for谓语，a greater proportion为同位语，修饰前面整个名词短语。
考点：
指代一致(Agreement)
1. which就近指代名词，不能指代完整的一句话;
2. it在文中，会继承被指代对象的特性，业即本文中，it 如果指代 a great proportion或者 the spending ，都继承了a great proportion或者 the spending 发生在presidential campaign of 1992的.特性，造成比较的逻辑关系错误，要引以注意。
3. 比较对象的内容，时态关系，逻辑含义均要对等。
选项分析：
(A) it指代的是a greater proportion整个短语，错误，应该用that来指代proportion，但是因为只是名词短语的比较，that可以省略而不带任何歧义。
(B) Correct;原句补完整：Soaring television costs accounted for more than half the spending in the presidential campaign of 1992,
a greater proportion than(the proportion)(television costs had accounted for of the spending)in any previous election。
(C) 现在完成时使用错误，in any previous election说明应用过去完成时;they指代soaring television costs，使逻辑意义错误，比较结构需要比较对象对等，前者为a great proportion 是一个量词不能和具体的费用对比，而且其他的election不一定是soaring的;同时have been与前面的accounted for不平行，只要也要用have done。
(D) Which不能指代前面整个idea;so用于省略重复的动作，使用错误。
(E) Which不能指代前面整个idea;it指代不清，且has been时态与后面的in any previous election不符。
以上就是对于GMAT语法实例分析的全部内容，值得注意的是考生朋友在拿到GMAT语法题是需要先将原句进行，并能找出GMAC想考察我们哪方面的考点，最后在将选项进行对比，最后祝大家都能考出好成绩。