单项选择题 The mariner must be the final judge of the reliance he can place on the information given in the Admiralty charts and other publications,since they（）.

单项选择题 A light is（）from Changshanzui,the SE extremity of the island.

单项选择题 Integrated Bridge and Navigation Systems(IBS/INS) provide excellent performance and reliable navigation under all conditions by（）.