Typical rates of sea-floor spreading are approximately 50 centimeters per year 5 centimeters per year 5 kilometers per year 5 meters per year

5 centimeters

Explanation:

The seafloor is spreading at rates of around 5 cm usually, though it can go up to 16 cm per year but rarely. The seafloor spreading is caused by the geological activity at the places where there's divergent plate boundaries. As the plates move away from one another they leave thin and fragile crust behind which is easy to break through for the magma. As the magma gets through and reaches the water, it starts to cool off very quickly, constantly pulling up and creating new crust, pushing the old crust sideways and further away from the divergent boundary.

cuban communists pressured the soviet union to place missiles in cuba.

yes

explanation:

the fighting words doctrine, in united states constitutional law, is a limitation to freedom of speech as protected by the first amendment to the united states constitution. in 1942, the u.s. supreme court established the doctrine by a 9–0 decision in chaplinsky v. new hampshire.