The boy who admitted in the exam promised the teacher that he would work hard at his le

问题补充：

The boy, who admitted in the exam, promised the teacher that he would work hard at his lessons.

A. cheat

B. to cheat

C. cheated

D. cheating

答案：

A. cheat

B. to cheat

C. cheated

(答案→)D. cheating

解析：句意：那个小男孩承认他在考试中作弊，向老师许诺他以后要努力学习。admit后可以接动名词，不可以接不定式。故选D。