Which of the following was a challenge faced by the earliest overland explorers?

a. uneasy relationships with native american
b. an undependable food supply
c. the lack of maps to chart their passage
d. all of the above

Ineed answers 5 and 6 on my social studies homework reply to this question i posted

Which of the following inventions most directly allowed ancient farmers to produce a surplus ?

By the end of the 1800s, there was a change in the nature of the immigrants coming to the united states. immigration from northern europe—england, ireland, germany, and scandinavia—declined, while immigration from italy, russia, and austria-hungary grew. in fact, between 1900 and 1910, more than three-fourths of all immigrants came from these three countries. unfortunately, these countries were far removed england, the home of our founders, and the immigrants who came from them had a hard time adjusting to life in their new country.