How have native americans contributed to our lives today

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 action best represents the policy of appeasement followed by britain and france prior to the start of world war ii? (a)allowing hitler to annex the sudetenland as part of the munich agreement (b)signing the nazi-soviet pact binding hitler and stalin to peaceful relations (c)sending troops to fight with the liberals during the spanish civil war (d)forbidding the sale of arms to any nation at war

How would having more railroad tracks be advantageous during a war