单项选择题 When the ship is under attack by pirates,or terrorists,（）needs to be activated.

单项选择题 Which of following physical abilities is not required as to the routine movement around a vessel?（）

单项选择题 The information regarding ports such as buoyed channels,fairway,location and number of terminals,river channels,details of navigational marks,location of overhead bridges, underground cables etc. are shown in（）