Question

---he police have caught the murderer.

---Yes, and he admitted ______ his boss on a rainy night seven years ago.

1. A.
   to kill
2. B.
   to have killed
3. C.
   having killed
4. D.
   have been killing

Answer 1

C
在delay，admit，avoid，suggest，advise，practise，finish，mind，enjoy等动词后，只跟动名词而不跟动词不定式作宾语。A、B选项是动词不定式形式，不能用在admit后；D中选项是谓语形式，也不对；C是动名词的完成时态形式，符合句法和题意的要求。