wet behind the ears
缺乏经验或成熟，年轻且无知
口语·批评缺乏经验
英文释义
lacking experience or maturity; inexperienced or naive
例句
Don't trust him with the project; he's still wet behind the ears.
典故来源
源自动物幼崽出生时耳朵潮湿，比喻人缺乏经验、稚嫩。