The net productivity per gang-hour can be improved through a decrease of（）.

A.Date and description of each failure
B.Average load in pounds for each usage
C.Total number of lifts for each usage
D.All of the above

A.less jerky starts
B.less jerky stops
C.overheating worries
D.none of the overheating worries

A.breaking a cargo runner
B.parting guys topping lifts
C.carrying away a block
D.overheating the resistors and eventually burning out