Simplify the following text for a Grade 11 native English-speaking person.
Original: East Germany closed the borders between East and West Germany and sealed off the border with West Berlin in 1952 ; but because of the quadripartite Allied status of the city , the 46 k-long sectorial border between East and West Berlin remained open . As there was freedom of movement between West Berlin and West Germany , Easterners could use the city as a transit point to West Germany , usually traveling there by air .
Simplified: East Germany closed the borders between East and West Germany in 1952 , but did not seal off West Berlin ; because there was freedom of movement between West Berlin and West Germany , Easterners could use the city as a crossing point to the West .