The Atlantic Ocean between the east coast of the United States and the west coastof Africa is about 6,000 kilometers (km) wide. The age of the oceanic Lithosphere between them is 280,000,000 years old. What is the average rate of seafloor spreading?

Which source would best a historian understand the effect of the great chicago fire on families? a. a biography of a chicago family displaced by the fire b. a letter from a grandmother in new york to her family in chicago c. a newspaper editorial about families who were displaced d. an oral history dictated by an adolescent who fled the fire

By choosing to resupply fort sumter, abraham lincoln risked a. abandonment of the fort by union soldiers. b. abandonment of the fort by confederate soldiers. c. the appearance of giving in to confederate secession. d. armed conflict with southern soldiers.

The stamp act: was passed by parliament in 1776 caused the boston massacre was the first direct tax levied by england on the colonists sparked protest in the colonies