问题：
[单选] It is abnormal that when the engine is being turned by the turning gear or by hand, （）.
water discharges from the indicator cocks。no water is leaking into crankcase。no water in the scavenge belt。the rpm is lower than the speed of Dead Slow Ahead。
问题：
[单选] It is important that the water （） very often as this can lead to increased deposits.
not be changed。be changed。should not be changed。should be changed。
问题：
[单选] It is important to use only pure lead and to choose a thickness of wire which is greater than the normal allowable clearance but （） this amount.
not less than twice。greater at least twice than。not greater twice than。larger three times tha。
问题：
[单选] It is necessary for us （） after having served for a certain period.
to change the lube oil。have the lube oil purified。have the lube oil burnt。to analyze the lube oil。
问题：
[单选] It is necessary to remove （） from the cooling spaces.
scar。scale。spur。bilge。
问题：
[单选] It is very important that each cylinder should be （） scavenged before the charged air is compressed.
well。good。excellent。respectively。
问题：
[单选] It is very necessary that each cylinder （） before the charged air is compressed.
is scavenged。is atomized with fuel oil。be scavenged。be atomized with fuel oil。
问题：
[单选] It is very necessary that each cylinder （） before the charged air is compressed.
is scavenged。has been scavenged。be scavenged。was scavenged。
问题：
[单选] It is well known that good lubrication will （） the bearings from becoming overheated.
present。prevent。avoid。provide。
问题：
[单选] Keep compartment （） as the gas given off can be dangerous.
well ventilated。well clean。in good order。more room。
