单项选择题
A.10°~20° B.20°~30° C.30°~40° D.40°~50°
A.103Ω•m B.105Ω•m C.106Ω•m D.109Ω•m
A.基极、发射极、集电极 B.阳极、阴极、集电极 C.阳极、阴极、门极 D.基极、发射极、门极