97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項選擇題

However, where immediate action is necessary to ensure safety of the ship, its machinery and crew, it must be taken by the engineer in chargeWhat dose “it” mean in the sentence above?（）

A.safety
B.the ship, its machinery and crew
C.immediate action
D.the engineer in charge

你可能感興趣的試題

單項選擇題

There will usually be summaries or daily account tables for heavy oil, diesel oil, lubricating oil, and fresh water, which will be compiled（）

A.at the beginning of every watch
B.at the beginning of the first watch every day
C.at the completion of every watch
D.at noon every day

單項選擇題

According to the principle of two stroke diesel engine, what is the number of its efficient work stroke per revolution?（）

A.1/2
B.1
C.2
D.3