( )him a few words of Italian? the waiter A. who taught b.who did teach 选A为什么不选B

过去谁教他一些意大利语的? 服务员教的
这里是who引导的特殊疑问句,要用陈述句的语序
特殊疑问句有两种语序
　　1．如疑问词作主语或主语的定语,即对主语或主语的定语提问,其语序是陈述句的语序：疑问词（+主语）+谓语动词+其他成分.如： 　　Who is singing in the room﹖ 　　whose bike is broken﹖ 　　
2．如疑问词作其他成分,即对其他成分提问,其语序是：疑问词+一般疑问句语序?　如： 　　What class are you in﹖ 　　What does she look like﹖ 　　Where are you from﹖ 　　What time does he get up every morning﹖ 　　How do you know﹖