What year was water fluoridation introduced?

Did the both the us and ussr have atomic weapons after 1949

Which of these did the soviet union do in 1961? it built a wall through berlin to keep people from moving to the west. it used force to destroy a wall the united states had built in berlin. it convinced the british and french to merge their zones in berlin with the soviet zone. it threatened to bomb berlin if the united states did not leave within 30 days.

In the early 1800s, north africa was different from southern africa in that