比如下这句:
She acknowledged ________ at fault.
A. to have been
B. having been
是选不定式的完成式还是动名词的完成式?
acknowledge作为“承认, 供认”时,用法和admit用法类似。
admit doing, admit having done sth, acknowledge having done sth 承认做了某事
例如:He acknowledged having made a mistake. 他承认他做错了。
所以上面一题的答案是B。