Three of the earliest civilizations developed on the same continent. what was the name of this continent?

What deadly disease cost many workers their lives before dr. william gorgas found a treatment?

What does jefferson mean when he writes"and to provide new guards for their future security"?

The term 'white man's burden" refers to the difficulty of converting colonists to christianity. the belief that europe had a duty to civilize other people. the conviction that white people were superior to all others. the struggle to survive in an increasingly industrialized world.