问题补充：
复合宾语的被动语态：原来的句子是“主语＋谓语＋宾语＋宾语补足语”,在变被动语态的时候只能将宾语变为被动语态的主语,宾语补足语变为被动语态的主语补足语.例如：They heard her sing an English song at the party.他们在晚会上听到她唱了一首英语歌.变为被动语态是：She was heard to sing an English song at the par
答案：
She was heard singing an English song at the party. 这句中原来的宾语补足语变成了主语补足语,所有的这种情况都是这样变化.
======以下答案可供参考======
供参考答案1:
She was heard singing an English song at the party.
供参考答案2:
she was heard singing an English song at the party
将主句的宾语变为主语，谓语为被动语态，补语不变。
复合宾语的被动语态：原来的句子是“主语＋谓语＋宾语＋宾语补足语” 在变被动语态的时候只能将宾语变为被
