When the teacher criticized him, he quickly retorted that the homework was already done.

retorted 是动词 retort 的过去式。retort 由前缀 re-（表示"回、反"）和词根 tort（来自拉丁语 torquere，表示"扭转"）组成，字面意思是"扭转回去"，引申为"反驳、回嘴"的意思。在句中表示对批评的快速反驳。