问题：
[单选] On top of scavenging air box is mounted a strong cast iron frame for each cylinder known as（）
cooling jacket。cylinder liner。piston crown。cylinder cover。
问题：
[单选] Once a fire is detected the engine should be slowed downOn no account （）.
the trunking should be opened up。should the trunking be opened up。the trunking should not be opened up。should the trunking not be opened u。
问题：
[单选] Once a scavenge fire is detected the engine （）.
will be speeded up。should be slowed down。must slow down。have to be slow dow。
问题：
[单选] Once a scavenge fire is detected, fuel should be shut off from the affected cylinders and cylinder lubrication increased （） the risk of seizure.
to protect。to guard。to maximize。to minimize。
问题：
[单选] Once all cylinders are firing regularly, （） is shut off.
the exhaust valve。the starting air。the inlet valve。the fuel oil。
问题：
[单选] Opening of the cylinder （） will admit compressed air into the cylinder.
safety valve。indicator cock。blow-down valve。start valve。
问题：
[单选] Operating conditions in the crank chamber are very （） those in the cylinder.
the same as。similar to。separated from。different from。
问题：
[单选] Piston No2 of main engine has been removed, and it will be （） by noon tomorrow.
lifted。reassembled。dismounted。disassembled。
问题：
[单选] Pistons may be made in （） in order to keep the weight down for balancing purposes at high speed.
cast iron。forged steel。stainless steel。aluminum alloy。
问题：
[单选] Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.
lead。forged steel。alloy steel。aluminum alloy。
