How many years did the Berlin Wall divide the Berliners?

What percentage of people in britain lived in cities in 1850? a.) less than 5% b.)between 6 and 10% c.) more than 20%

Webster states that, "the constitution does not provide for events which must be preceded by its own destruction." what does he cite as an event that would destroy the constitution?

How many concentration camps did the us shut down?