ATPL: Consider a jet engine whose control is based on the Engine Pressure Ratio (EPR) 1. with a constant EPR, the thrust decreases when the altitude increases 2. with a constant EPR, the thrust is independent of the Mach number 3. At same environmental conditions, a given EPR setting maintains the thrust irrespective of engine wear due to ageing. 4. the EPR is determined by the impact pressure difference between the turbine outlet and the compressor inlet 5. on take-off, in the event of icing not detected by the crew, the indicated EPR is lower than the real EPR The combination regrouping all the correct statements is: