【单选题】---Alice, why didn’t you come the other day ? . ---I______, but I had an unexpected visitor.
【单选题】-Why didn't you come to the concert last night? -I_________,but I had an unexpected visitor. [ ]
【判断题】无论是哪种三极管,当处于放大工作状态时,基极电位总是高于发射极电位,集电极极电位也总是高于基极电位。
【判断题】无论是哪种三极管,当处于放大工作状态时,基极电位总是高于射极电位,集电极电位也总是高于基极点位
【简答题】Why had the visitor come to the House of Usher?
【判断题】无论是哪种三极管,当处于放大状态时,基极点位总是高于发射极电位,集电极点位总是高于基极电位。