1. Due to centuries of migrations, there were few places on Earth that
humans did not

i'm not sure i understand what you are trying to ask, if you give more information, that would be most .

by 1890, the united states had by far the world's most productive economy. american industry produced twice as much as its closest competitor--britain. but the united states was not a great military or diplomatic power. its army numbered less than 30,000 troops, and its navy had only about 10,000 seamen. britain's army was five times the size of its american counterpart, and its navy was ten times bigger. the united states' military was small because the country was situated between two large oceans and was surrounded by weak or friendly nations. it faced no serious military threats and had little interest in asserting military power overseas.

all choices are correct

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories