During an engine room watch if immediate action is necessary to ensure safety of the ship its machinery and crew _____.
A.the chief engineer must be informed at first
B.the captain must be informed at first
C.it must be taken by the duty engineer
D.the generator engine must be stopped
请帮忙给出正确答案和分析,谢谢!
热搜:n维列向量组a1,an-1线性无关,且与非零向量正交