If air at 95 'C dry bulb temperature and 50% relative humidity is conditioned to 75 C dry bulbtemperature and 50% relative humidity, it is an example of( )
A. cooling only
B. cooling and humidifying
C. cooling and dehumidifying
D. adiabatic cooling
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Which of the following functions is NOT one of the functions of air conditioner?( )
A. Refreshing the air.
B. Waking up.
C. Adjusting the air humidity.
D. Adjusting the air temperature.
A wise precaution for an engineer to take is to go through accommodation and public roomsperiodically recording( )
A. dry bulb temperature
B. wet bulb temperature
C. wet and dry bulb temperatures
D. air humidity
切削速度的计算公式()是正确的
A. vc=πdn/1000
B. vc=dn/1000π
C. vc=dn/1000π
D. vc =πn/1|000d
下列选项中不是影响切削变形的因素是()。
A. 工件材料
B. 进给量
C. 刀具前角
D. 切削速度
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