What natural resources were American seeking out west

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.

Which common characteristic of renaissance buildings does this image show

An individual who is experiencing a prolonged period of stress would likely have levels of circulating than an individual who was not experiencing stress.