（） are fitted in the exhaust system and facilitate charge removal and scavenging in each cylinder.

A.Pneumatic pipes
B.Hydraulic pipes
C.Telescopic pipes
D.Operating gas pipes

A.The ballast system
B.The salt water system
C.The bilge system
D.The domestic system

A.A relief valve
B.An alarm
C.A pressure gauge
D.A non-maim valve