than结构的使用差异比较GWD1-Q16；GWD3-Q30

GWD1-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.

A.    a greater proportion than it was

B.    a greater proportion than

C.    a greater proportion than they have been

D.    which is greater than was so

E.     which is greater than it has been

答案：B

Today’s technology allows manufacturers to make small cars more fuel-efficient now than at any time in their production history.

A.    small cars more fuel-efficient now than at any time in their

B.    small cars that are more fuel-efficient than they were at any time in their

C.    small cars that are more fuel-efficient than those at any other time in

D.    more fuel-efficient small cars than those at any other time in their

E.     more fuel-efficient small cars now than at any time in

答案：C。

请问下这两题考点上的区别。第一题than后面直接加的介词结构，第二题than后面要先补上those再加介词结构。请问为什么会有这样的区别呢？是否第一题应该理解为than后同时省略了相同的主谓，但是如果是这样理解，为什么第一题than 后面存在原来的那个谓语，但是第二题than后面只有those这样一个代词不存在谓语呢？请nn帮忙分析下这两道题结构上真正的差异。

同一个主语在不同的时间条件下比较时than后面的 it is等词语可以省略掉的

一般有代词出现反而容易造成歧义

第二题中的对象不完全一直 一个是节能的car than之前不节能的car 所以后面不能省略

还有就是 这里要用any other time 

up!

第一题比较的是不同时间的两个election：the presidential campaign of 1992和any previous election.当前后主谓一致时可以省略，但是介词不能省。

第二题比较的是cars.比较对象不能省，因此要补出来。

那A补出it会造成什么歧义呢？

这样说的话就很好理解了，可是如果理解成不同election的proportion在作比较又有什么错呢？

这么说的话，第一题的proportion和第二题的propotion应该是同名同物吧？