adj.秘密工作的，暗中做的，私下进行的

The journalist went undercover to expose corruption within the government agency.
记者卧底以揭露政府机构内部的腐败现象。
The police officer had been working undercover for months, infiltrating the drug cartel.
警官已经卧底数月，成功渗透到贩毒集团内部。
She took an undercover job at the factory to investigate labor abuses.
她在工厂找了份卧底工作，以便调查劳动侵权行为。
The reality TV show sent participants on an undercover mission to test their survival skills.
真人秀节目派参与者执行卧底任务，以测试他们的生存技能。
The detective posed as a buyer in an undercover sting operation targeting illegal arms dealers.
侦探在针对非法军火商的卧底诱捕行动中假扮成买家。
He wrote a book about his experiences working undercover in organized crime.
他写了一本关于自己在有组织犯罪中卧底经历的书。
To gather evidence, the wildlife conservationist worked undercover at a poaching syndicate.
为了收集证据，这位野生动物保护主义者在偷猎团伙中从事卧底工作。
The company hired an undercover auditor to assess employee adherence to safety protocols.
公司聘请了一位卧底审计员来评估员工对安全规程的遵守情况。
The spy spent years living undercover in a foreign country, gathering intelligence for her government.
间谍在外国卧底生活多年，为本国政府搜集情报。
In order to expose the unethical practices of the sweatshop, the activist worked undercover as a seamstress.
为了揭露血汗工厂的不道德做法，该活动人士以裁缝的身份卧底工作。