The ancient Incas did not use an alphabet of written letters to communicate important messages. Instead, they invented a complex system of knotted strings called quipus. The quipus performed a rich diversity of uses that included tracking population changes, counting grain inventories, and assessing tax obligations.
About 1,400 Incas quipus still survive. However, they remain largely undeciphered. SAT test writers are aware of the research currently being conducted by Manuel Medrano to better understand the quipus. His ground-breaking statistical work will SUPPLEMENT or add to and improve the existing historical reports.
It is important to point out that Medrano’s statistical data will not SUPERSEDE or replace historical reports. SUPERSEDE is now making frequent appearances on vocabulary in context questions as both a correct and an incorrect answer.
SUPPLEMENT – add to and improve
SUPERSEDE – take the place of something