单项选择题
A.oil fires in the engine room bilges
B.class B fires in paint lockers
C.any class D fire
D.all of the above
单项选择题 Which of the following statements concerning the water tube and fire tube boilers is not true?（）
单项选择题 Which one of following statement is not true concerning the suitable sites of the direct acting relief valve and the pilot operated relieve valve?（）
单项选择题 In heavy marine engine the practice is to drive the engine on（）which has previously been stored in starting air reservoirs.