A.Oil is discharged from the impeller through the outlet
B.Gravity causes the oil to flow toward the discharge
C.The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts
D.The discharge capacity varies directly with the speed of the impeller

A.distance of the suction liquid level above the line of the pump
B.distance the suction liquid level is below the center line of the pump
C.force necessary to overcome frictional losses in the pump and piping
D.amount in inches of mercury the total suction head is below atmospheric pressure