Ethnocentrism is the belief that your culture is superior to all others.
Key terms such as, contact zone, autoethnography and transculturation are introduced in her essay. The first problem this this essay is that you are using too many long sentences.
With such culture variation, United States is seen as a vast country. The humans were not aware what they had done; there for the cultural contact between these two cultures became extremely bad really fast.
Contact zones are where people are meeting other cultures, and they have to remember not to lose their own. In "Arts of the Contact Zone" Pratt discusses the mix of two different cultures in one area.
You need to cut these down to shorter but complex sentences in order to improve your GRA score. Thirdly, American focuses on progress and change.