A.RC B.LC C.石英晶体 D.集成运放 E.分立元件
A.电感 B.电容 C.电阻近似为零
A.约为50% B.约为78% C.大于50%,小于78% D.大于78%
A.外差 B.差频 C.频偏
A.2085kHz B.1740kHz C.1275kHz D.1075kHz