【单选题】For airplane ground operations, AC power comes from one of these sources: external power panel; auxiliary power unit(APU) generator. For in-flight operations, power comes from an integrated drive gene...
A.
AC means the alternating current
B.
generator means a company that produces electricity to sell to the public
C.
panel means a group of people who discuss topics of interest on television or radio
D.
IDG means a generator drived by the engin directly