单项选择题
A.use the mouth-to-mouth method
B.clear airways
C.use rhythmic pressure method
D.know all approved methods
单项选择题 Safety is dependent on orderliness and cleanlinessOrder may be maintained by （）
单项选择题 To safeguard the operator and other personnel working on or near a hoisting operation which of the following precautions should be observed?（）
单项选择题 Which of the actions listed and instituted on your part will have the greatest lasting effect on the crew with respect to safety?（）