At the party, Lucy         like a Mickey Mouse to make us        .

A．dressed up, laugh

B．dressed up, to laugh

C．dressed on, laugh

D．dressed on, to laugh

当电力系统发生A相金属性短路时，故障点的零序电压（）

A、与A相电压同相位

B、与A相电压相位相差180°

C、超前于A相电压90°