Q16:

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.

1. a greater proportion than it was
2. a greater proportion than
3. a greater proportion than they have been

4. which is greater than was so

5. which is greater than it has been

答案是B 请问A为何不对

在比较中 一般来说时态不同 要补出助动词

谢谢

A的it不能指代a greater proportion；而且accounted和was并无法表达时态的不同，恰恰相反，两者用了同一个时态－一般过去时；其实，这里的比较可以被看作，the proportion in the campaign of 1992 was greater than (that) in any previous election.

原句补充完整是Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than the proportion soaring television costs accounts for in any previous election.