单项选择题
A.should be correctly carried out B.should correctly be taken place C.should carded with care D.must to carry out with great care
To avoid scavenge fires （） the engine timing and equipm...
单项选择题To avoid scavenge fires （） the engine timing and equipment maintenance should be correctly carried out.
A.occurred B.occurring C.not happening D.occur
Those generally used additives for cooling water are ei...
单项选择题Those generally used additives for cooling water are either anti-corrosion oils or inorganic（）.
A.gases B.paints C.inhibitors D.detergent
This used piston had been tested and approved as a spar...
单项选择题This used piston had been tested and approved as a spare part by the （） during last annual repair.
A.agent B.shipchandler C.surveyor D.engineer
