Why was the Cuban Missile Crisis a serious threat to the world?

Why was the Cuban missile crisis a threat to world peace? It was a threat to world peace because it changed the balance of power between the US and the USSR. By stationing nuclear missiles in Cuba, the Soviet Union attained the ability of hitting the US within minutes, long before the US could retaliate.

Explanation:

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.

this is not a question its simply asking you to read and write a few sentences and   the question on the bottom its fairly easy, you can do this!