Engine parts, What are the features of an engine? I need help before tomorrow

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Inspection for bearing condition will include: (clo4) a)-color b)-smell c)-size d)-none of the above

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?