单项选择题
A.lubricant B.coolant C.combustion product D.second refrigerant
If （） are taken at regular intervals, any unequal distr...
单项选择题If （） are taken at regular intervals, any unequal distribution of load will be easily found out.
A.differential of crank-webs B.indicator diagrams C.lube oil reading out D.misalignment of crank-throws
High-speed rotating in a centrifugal purifier can produ...
单项选择题High-speed rotating in a centrifugal purifier can produce a force （） larger than the force of gravity.
A.many thousand times B.between times C.one time D.at times
Here some oil in the oily water separator, as a result ...
单项选择题Here some oil in the oily water separator, as a result of its lower （）, will separate and rise into the oil collection space.
A.temperature B.viscosity C.density D.velocity
