单选题
1分
Before “stand-by” is rung on the engine telegraph, it is usual to give the main engine ____ ahead an...
Before “stand-by” is rung on the engine telegraph, it is usual to give the main engine ____ ahead and astern.
参考答案: C
参考解析: 在车钟给出“备车”车令前,通常要对主机进行简短的正倒车试车。