单项选择题
Personnel working aloft (above 2metres) should wear（）or other arresting device at all times.
A.a safety harness with lifeline B.a safety net C.a life buoy D.buoyancy agarments
单项选择题 （）should generally best for handing acids,alkalis,various types of oils,solvents and chemicals in general.
单项选择题 （）should generally be used when handing rough or sharp objects.
单项选择题 Long hair should always be covered by（）when working with or near moving machinery.
