被动语态的一般疑问句如何修改.His bike was stolen last night.

Was his bike stolen.被动语态的句子从陈述句改为一般疑问句时和主动语态的句子没有差别,原句是主系表结构（His bike是主语,was是系动词,stolen是标语,last night是时间状语）,如果你改成Was his bike be stolen,请问这个be是干什么用的?它就多余了,改好句子后看看句子是不是多余或缺少成分,就万无一失了.