题目类型：
问答题
题目内容
In “Detective on the Trail,” Bob Sugg knew that the man in police uniform was the criminal because the real policemen were dressed in _______.
正确答案
plain clothes
题目解析
原句的意思是“在《Detective on the Trail》这篇课文中，Bob Sugg知道穿着警服的这个男人就是罪犯，因为真正的警察是穿便服的”。