关于it和that指代难理解的两题，一周考试求指教！

ccfish9

最近在复习Prep SC有两题it和that指代不大清楚，根据解释it为精确指代，that仅指代中心词，如何判断it指代的具体内容呢？

197. Soaringtelevision costs accounted for more than half the spending in the presidentialcampaign of 1992, a greater proportion than it was in any previouselection.
A. a greaterproportion than it was
B. a greaterproportion than
C. a greaterproportion than they have been
D. which isgreater than was so       (B)
E. which isgreater than it has been


本题答案B原因是it指代a greater proportion错误应用that而that可省。

There are hopefulsigns that we are shifting away from our heavy reliance on fossil fuels: more

than ten times asmuch energy is generated through wind power now than it was in1990.    

(A) generatedthrough wind power now than it was

(B) generatedthrough wind power now as it was

(C) generatedthrough wind power now as was the case

(D) now generatedthrough wind power as it was

(E) now generatedthrough wind power than was the case

本题答案C，不考虑习惯性用法仅看it指代，解答说B错在It精确指代“现在通过风能产生的电力”，这个电力不可能再出现在1990年。

小女疑问：该如何判断it指代的具体内容？谢谢解答！
有兴趣或疑惑的各位欢迎参与讨论啊~

bonfin

1.要用it则必须有明确先行词，第一题比较的是比例，而句子前半句没有具体表示比例的名词，所以不能用it。
2.it表示“同一个”，两年的电力是不同的事物