How european exploration led to columbian exchange

Which answer best explains the overall impact of the chicken on native american populations in the new world? negative; it destroyed much needed grain crops neutral; it was not well adopted by native americans insignificant; other animals were more quickly accepted positive; it brought a good source of protein to the native american diet

What is one example of trench warfare ?

Capitalism competed with dominance in the twentieth century communism merchantilism free enterprise feudalism