Definition: someone who tries to find out secret information, especially about another country Level: B2
他是政府的一名秘密特工。
He is a secret ___agent for the government.
她打断并告诉那个人她是一名秘密特工。
She interrupted and told the man that she was a secret ___agent.
这名卧底特工渗透进了敌方组织。
The undercover ___agent infiltrated the enemy organization.
