He was attired in a plain, mud-flecked uniform.

他身穿一件朴素而沾有泥点的制服。

《柯林斯英汉双解大词典》

He was a hardened soldier who "dressed simply in a plain cotton uniform with straw sandals," Ms. Pakula writes, and neither drank nor smoked.

Pakula女士写道，他是一个“身穿简朴的棉军装，打着草鞋”的坚毅士兵，既不喝酒，也不抽烟。

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Combatants will be in uniform or will wear specially introduced and clearly distinguishable badges. Fighting in plain clothes or without such badges is prohibited.

战斗人员必须穿制服，或佩带特别指定的和清楚易辨的徽章标识。禁止穿便服或不带这种徽章标识作战。

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The Superintendents' Association, which represents senior officers below the rank of chief constable, argues that officers could patrol alone, rather than in pairs, and detectives could work in uniform, rather than in plain clothes.

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