It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）.

A.gums, acids, and varnishes
B.removed by cellulose type filters
C.neutralized by oil additives
D.not removed by absorbent filters

A.repack all valve stems
B.lubricate it prior to use
C.replace the foundation bolts
D.balance the warping heads

A.blue
B.green
C.orange
D.purple