Domanda 612, Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot license

With the setting on "normal", the cockpit crew is supplied with a mixture of oxygen and cabin air .
With the setting on "NORMAL", the passengers are supplied with a mixture of oxygen and cabin air.
The same source of supply is used by the cockpit crew and cabin crew.
The Same Source Of Supply Is Used By The Cockpit Crew And Passengers.