单项选择题
A.evaporator pressure decrease
B.evaporator coil over-feed
C.evaporator capacity increase
D.expansion valve diaphragm rupture
单项选择题 It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）.
单项选择题 Water allowed to accumulate in the hydraulic system oil will cause an oxidation process producing by- products which are normally （）.
单项选择题 If an anchor windlass has been idle for some time, you should （）.