单项选择题 The profit from the camage of cargo,which is often called（）,keeps the mer-chant ship running.

单项选择题 Which of the following statements concerning cargo is correct?（）

单项选择题 Before work is commenced（）,the officer responsible should inform the duty en-gineer to ensure that steps are taken to reduce as far as practicable the emission of steam, harmful gases and fumes.