1) Two combined zones 
The Bizone, or Bizonia was the combination of the American and the British occupation zones in 1947 during the occupation of Germany after World War II. With the addition of the French occupation zone in April 1949 the entity became the Trizone (sometimes jokingly called Trizonesia, as, for example, in a well-known Karneval song from that time). L...
two combined zones.