后天就考试了 各位大牛们帮帮忙 一个it 与that的指代

freyang

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

Between 1990 and 2000 the global economy grew more than it did during the 10,000 years from the beginning of agriculture to 1950.
A.    Between 1990 and 2000 the global economy grew more than it did during the 10,000 years from the beginning of agriculture
B.    Between 1990 and 2000 the growth of the global economy was more than that during 10,000 years, from when agriculture began
C.    The growth of the global economy between 1990 and 2000 exceeds that which had been for 10,000 years from the beginning of agriculture
D.    The growth of the global economy between 1990 and 2000 exceeds what it has been for 10,000 years, from when agriculture began        
E.    The growth of the global economy between 1990 and 2000 exceeded what it did for the 10,000 years from the beginning of agriculture


第一题要选B 因为 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

但为什么第二题 选择A 就不会继承 Between 1990 and 2000 这个特性呢

谢谢大家帮忙啊

小困蛇

你第一题B没抄错吗

第二题 A 感觉前面时间状语做插入语