She was heard __A______ an English song.A.to sing B.sing C.sang D.to be sang 写下详解（语法）
问题描述：
She was heard __A______ an English song.A.to sing B.sing C.sang D.to be sang 写下详解（语法）
答
这个句子是hear somebody do something所变成的被动结构.在主动结构中,动词不定式做hear的宾语补足语时,要省略to,但在变成被动结构时,动词不定式符号to就不能省了.