Ron a question for you with respect to the Note 2.2 :
First, you can't have exactly the same noun on both sides of the comparison, so "it" is barred from standing for whatever is in the other half of the comparison.
I have copied this from your explanation from Manhattan site . Since I have read this, I was thinking I have misunderstood something and now, I found the question to get it clarified . There you go with another GMATPrep :
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 to 1950.
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.
OA iS
A
Could you explain usage of it here in reference to the quote from your post. It looks I misinterpret your statement by thinking that bolded it
can not be used for subject ion left hand side , which is the global economy .
I have no other issue with this question.