What is a example of a primary source

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.

Give a brief summary/define the holocaust - who was behind it, how it began, what was the goal, and where did it take place? (8-10 sentences). be sure to include at least 2 pictures or a timeline

Give an example of a situation in which an individual's pursuit of economic self-interest may not benefit but instead harm the rest of society