单项选择题
---Dead slow ahead! ---Reply: （）. ---Report: Engine dead slow ahead.
A. No problem B. OK C. Dead slow ahead D. Yes
单项选择题 ---Stand by engine! ---Reply: Stand by engine! ---Report: （）.
单项选择题 Stand by engine. （）
单项选择题 The duty （） should do the cleaning work every morning.
