请教pre07第49题

rainygo

原题+解释如下：
“49. (27096-!-item-!-188;#058&003405)

Since 1990 the global economy has grown more than it did during the 10,000 years from the

beginning of agriculture to 1950.

(A) Since 1990 the global economy has grown more than it did during the 10,000 years from the

beginning of agriculture

(B) Since 1990 the growth of the global economy has been more than that during 10,000 years,

from when agriculture began

(C) The growth of the global economy since 1990 exceeds that which had been for 10,000 years

from the beginning of agriculture

(D) The growth of the global economy since 1990 exceeds what it has been for 10,000 years, from

when agriculture began

(E) The growth of the global economy since 1990 exceeds what it did for the 10,000 years from the

beginning of agriculture

句子结构：… the global economy has grown more than it did… 比较结构。

考点：比较、动词形式

1) 比较，相同比较对象的代词指代，代词that通常不单独使用，后面常跟of…。

2) 动词形式，from…to…连接两个过去的时间范围时，用一般过去时态。

(A) 正确，it指代economy，did指grow的过去时。

(B)  该选项是名词growth之间的对比，表达不准确，more than之间应该有形空词，如fast；from +when

引导的从句用法错误，介词from后面应该加名词。

(C) that指代错误，表达罗嗦不清晰；过去完成时态错误，应该用过去时态。

(D) it指代对象不清楚，表达罗嗦不清晰，且exceeds后面应该用过去时态，而不是现在完成时态；from

+when引导的从句用法错误。

(E) it指代对象不清楚，表达罗嗦不清晰。"

看了解释后，我有几个问题没想明白：
1. A选项是since...than...from...简单说来就是since... 这个句子没有主谓，全是介词短语，为什么会是对的呢？
2. 后面是during一个年代，为什么不用过去完成时had， 而用过去时呢？
3. 解释里面说选项D,E的it指代不清楚，我觉得很清楚啊，就是指代the growth啊。

还请牛人给指教一下。 谢谢！

rainygo

有人能给解释下吗？ 拜托拜托