---I regret you John has been fired---I can hardly believe my ears．He’s such a fine worke

问题补充：

---I regret you John has been fired．

---I can hardly believe my ears．He’s such a fine worker．

A. telling

B. having told

C. to tell

D. to have told

答案：

A. telling

B. having told

(答案→)C. to tell

D. to have told

解析：这题考查动词regret的用法：regret doing“后悔做了什么”，regret to do“很遗憾要做什么”，根据句意：--我很遗憾地告诉你约翰被开除了。选C。