Question 18, Performance and flight planning - PPL(A) - Private Pilot License

The point on the lateral axis of an aeroplane or its extension from which the centers of gravity of all masses are referenced.
The point on the vertical axis of an aeroplane or its extension from which the centers of gravity of all masses are referenced.
The point on the longitudinal axis of an aeroplane or its extension from which the centers of gravity of all masses are referenced.
The distance from the reference plane to the center of gravity of an aircraft.