<span>Missionaries would imposed their religious beliefs upon the native people. hope this helps!</span>
Dorothy Vaughan had six children, so it was really hard to commit to them and science at the same time. But this reconciliation was, in her case, a philosophical matter of private and public interest. What she did as a scientist helped her children too, just like so many other children, and humanity in general. As a mother, she naturally missed her children and wanted to spend more time with them; but she had this other mission as well, which was even more important, in terms of humanity.
Areas like the Indus Valley Civilization (India), Egypt and China developed advanced civilizations first. Yes, geography played an important role. All of these civilizations had large rivers to support agriculture, Indus river in Indus Valley Civilization, Nile river in Egypt and Yellow river in China.