单项选择题
A.the characteristics，efficiency and limitation of the radar equipment
B.any constraints imposed by the radar range scale in use
C.the effect on radar detection of the sea state，weather and other sources of interference
D.the safe working load of the cranes both on board and ashore
单项选择题 In determining if risk of collision exists，if there is any doubt，such risk shall be deemed to（）.
单项选择题 In determining safe speed，all of the following must be taken into account EXCEPT the（）.
单项选择题 When a vessel sees the other ahead or nearly ahead，by night she could see the masthead lights of the other in a line or nearly in a line or both side lights，（）shall be deemed to exist.