单项选择题 The Master of a cargo or tanker shall be responsible that each lifeboat，except those free-fall launched，is lowered to the water with crew and maneuvered at least once every（）.

单项选择题 The lifeboats and liferafts were（）with the provisions of the regulations annexed to the Convention.

单项选择题 The knife on an inflatable liferaft will always be located（）.