89. Please start main engine 3 times ahead and astern continuously.
A、
A、Runengineaheadfor3minutes.;
B、
B、Runengineasternfor3minutes.;
C、
C、Runengineaheadorasternfor6minutes.;
D、
D、Startengineaheadandastern3times.
发布时间：2025-05-21 18:12:28
