Why are so many ethnic cultures found in the United States? People from other countries built many businesses.
Schools teach students about different cultures.
Communities with many cultures are better run.
The country has a long history of immigration.

i think the answer is B.

Explanation:

The United States is ethnically and racially diverse as a result of large-scale migration throughout its history, and through African-American slavery and emancipation.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.  

answer; bill of rights;