单项选择题 A gas-free certificate would usually be issued by a(n)（）.

单项选择题 A complaint of unseaworthiness by a majority of crew members to the American Consul is found to be justified after a survey is completed. Who must pay the cost of the survey?（）

单项选择题 （）the incomplete nature of the survey，heavy draught vessels are warned not to navigate within the 10 fathom line.