Once in the exam, the students who’ve done it would be punished.
A. caught cheated
B. catching cheating
C. being caught cheating
D. caught cheating
网友回答
A. caught cheated
B. catching cheating
C. being caught cheating
(答案→)D. caught cheating
解析：考查固定结构。Catch sb doing sth抓住某人正在做某事。the students与catch构成被动关系，使用过去分词的形式。结合句意可知D正确。句意：一旦考试作弊的学生被抓住，这些学生会被惩罚。