The boy was seen _ the piano at 9 yesterday.A.to play B.play C.playing D.palyed
问题描述：
The boy was seen _ the piano at 9 yesterday.A.to play B.play C.playing D.palyed
我认为答案是A,被动语态要加to 为什么答案是C呢?
答
你说的感官动词和使役动词变为被动语态时,动词前面要加to,是针对主动语态的句子感官动词和使役动词接不带to的不定式作宾补说的.例如本句的make sb.do sth,see sb do sth.是强调看到动作的过程,变成被动语态时要加to,如：
I was made to take care of her baby that day.
另外,这些感官动词也可以接see sb.doing这种形式,是指在某个点时间,看到某人正在做某事,如果变成被动语态,也要用现在分词的形式.
本题中的是指某人当时被看到正在做什么,所以选C.