英文諺語(yǔ)：掛羊頭賣(mài)狗肉

After praising the wine they sell us vinegar.
     掛羊頭賣(mài)狗肉
     Explanation： to offer to give or sell something that is inferior to what you claim it to be.
     Example： that fellow completely misled us about what he was capable of doing. After praising the wine， he sold us vinegar.