问题补充：
He apologized for to inform me of the change in the plan.
A. his being not able
B. him not to be able
C. his not being able
D. him to be not able
答案：
A. his being not able
B. him not to be able
(答案→)C. his not being able
D. him to be not able
解析：考查动名词的否定，for是介词，用动名词做宾语，否定词not放在动名词前面，his是逻辑主语，句意：他因为没能及时通知我计划改变而道歉。选C。
