Acid solution（） in the system can be tested from time to time by putting some on to a piece of lime.

A.the pulse-phase system
B.the pulse Doppler system
C.the pulse system
D.the pulse interval

A.more than the working temperature
B.less than the working temperature
C.the working temperature
D.the same as the surrounding temperature

A.Pump diesel oil first
B.300 tons of 180 cst fuel oil
C.The figure is all right
D.OK, I’ll sign it