What was the cultural importance of the annual flooding of the Nile River?

What is the reason for the “scramble for africa”?

In the 1400s, portugal’s economy was based on a. industry b. exports c. finance d. trade

The first atomic explosion was detonated in the desert north of alamogordo, new mexico, on july 16, 1945. what percentage of the strontium-90 ( yr) originally produced by that explosion still remains as of july 16, 2016?