4. _________ is the process of removing exhaust gases from the cylinder after combustion
and replenishing the cylinder with fresh air.
(A) Compression
(B) Ignition
(C) Expansion
(D) Scavenging
17. The ___________ throttles the liquid refrigerant and maintains the pressure difference
between the condenser and evaporator.
(A) constant folw control valve
(B) constant pressure control valve
(C) pressure regulating valve
(D) expansion valve