Each piston stuffing box is provided with two sealing rings and three_____.A.packingsB.pis

The （) chamber is enclosed between the cylinder head and piston.

two men batter each other to pulp in the boxing ring.____________________________

Boxing Day is a holiday on which _________will receive the Christmas Box from their _

How heavy is this box？（英译中)

Air leakage between the shaft and stuffing box packing in a centrifugal pump is prevented

The lower end of each piston rod is reduced in diameter to fit a bore in _____.A.the cross