三态输门和普通与非普通的不同之处就是其输出端除了能输出“１”态和“０”态外，还可以出现一个（）状态 ["Ａ、高阻","Ｂ、低阻","Ｃ、１态","Ｄ、０态"]
能实现加法逻辑运算的电路称为（）门电路 ["Ａ、与","Ｂ、或","Ｃ、与或","Ｄ、异或"]
收音机、电视机的接收天线到无线接收电信号的幅度通常在（）上下 ["Ａ、千伏级","Ｂ、伏级","Ｃ、豪伏级","Ｄ、微伏级"]
并联谐振电路处于谐雪振状态时，电路中（）等于零 ["Ａ、阻抗","Ｂ、容抗","Ｃ、感抗","Ｄ、电抗"]
对账应注意哪些事项？
结账的注意事项有哪些？
