单选题The magician picked sever

问题补充：

单选题Themagicianpickedseveralpersonsfromtheaudienceandaskedthemtohelphimwiththeperformance.A.by accidentB.on occasionC.at randomD.on an average

答案：

C解析at random(=without aim or purpose)随便地，胡乱地：His clothes were scattered about the room at random.By accident意外地；on occasion偶尔；on an average平均计算。