Question id 219 - Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot license

Clear The Burnt Gases, The Expansion Of Which Provide The Thrust
Compress the air in order to provide a better charge of the combustion chamber
Drive the compressor by using part of the energy  from the exhaust gases
Drive Devices Like Pumps, Regulator, Generator.

Training tests and timed exam simulations ATPL - Airline Transport Pilot license