A. high speed water passing over the impeller blade.
B. tiny vapor bubbles travelling through the impeller.
C. explosion inside the pump.
D. lower saturation temperature of the water passing through the pump
Low birth weight may be caused by _ factors, such as smoking during pregnancy.Lo
The health problems 1 with fatness may not be caused by It but be another-|||-
[单选题]If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, theA．oil has a tendency to emulsify in the bowlB．purifier will act as a clarifier at the discharge ringC．oil will be lost through the water discharge portsD．o
[单选题]High-speed rotating in a centrifugal purifier can produce a force （） larger than the force of gravity.A . many thousand timesB . between timesC . one timeD . at time
[单选题]The fire pumps must be capable of delivering a total quantity of water at a defined head, not less than _____ of the total bilge pumping capacity.A．one-thirdB．two-thirdsC．one-fourthD．two-fourths
[单选题]G．ear pumps are widely used to transfer any one of the following but .A．fuel oilB．lube oilC．hydraulic oilD．fresh water
[单选题]The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.A . gearB . nonpositive displacementC . positive displacementD . rotary
[问答题] 什么是离心泵的汽蚀（Cavitation）？
[单选题]When fire pumps are used for other than firefighting service，each pipe connecting the other service (except for branch lines used for deck washing) must have a（）.A . check valve installed in the lineB . shut off valve at a manifold near the pumpC . q
[单选题]The accident was caused by ______.A． the driver of the first carB． the driver of the second carC． the driver of the third carD． both B and C