单项选择题
A shipmate chokes suddenly，cannot speak，and starts to turn blue. You should（）.
A.perform the Heimlich maneuver B.make the victim lie down with the feet elevated to get blood to the brain C.immediately administer CPR D.do nothing until the victim becomes unconscious
单项选择题 A right-handed propeller will cause the survival craft to（）.
单项选择题 A rescuer can most easily determine whether or not an adult victim has a pulse by checking the pulse at the（）.
单项选择题 A racetrack turn would be better than a Williamson turn in recovering a man overboard if（）.
