How did scientists reach their conclusions during the middle ages

Bonus question: according to wikipedia, in chinese philosophy yin and yang "describes how seemingly opposite or contrary forces may actually be complementary, interconnected, and interdependent." what are some examples from the story that amy tan may have intentionally incorporated elements of yin and yang philosophy into this story? select 2.

On this map, the state of georgia is in which section of the map?

Where is sub-saharan africa located?