GMAT Sentence Correction (SC) | Re: Passage of the Day

Here comes Passage for Feb 6

Hi e-gmat,

Appreciate you for new initiative!!!

Got answers for 1,2 and 5. But still challenge is how do you break the passage, it is single long sentence!!!

Could you please explain Question 3 & 4?

1. What is the belief about Aztec?
The belief that Aztec was constructed during two distinct construction periods

2. What are the two ways in which this belief has been proven?
By the modern tree-ring dating and other evidence found in the 1920s by archaeologist