单项选择题
A centrifugal pump can’t supply water after startingYou should check （）.
A.priming water B.power supply C.packing gland D.bearing lubrication
单项选择题 Open the （）of inter cooler before starting an air compressor.
单项选择题 Open the （）before starting an air compressor.
单项选择题 Supply the （）before starting an air compressor.
