A substantial increase in crankcase pressure could be an indication of ()
A. excessive lube oil pressure
B. the proper seating of new rings
C. a worn cylinder liner
D. a malfunctioning cylinder relief valve
接收机中加自动频率控制的目的是为了使接收机的频率()。
0.20mol/L乙二胺溶液的pH值为(Kb1=8.5×10-5、Kb2=7.1×10-8)()。
A. 11.62
B. 11.26
C. 10.52
D. 10.25