The oil has hardened to tar.

油已硬化成沥青了。

《柯林斯英汉双解大词典》

The rolling contact components are, as a rule, through-hardened by swiftly quenching the heated components in oil baths or salt baths.

在滚动接触组成部分，作为一项规则，通过硬的快速淬火油或盐温泉浴的加热元件。

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Main ingredients: green tea essence, almond oil, mint, cationic active agent, high elastic case-hardened cells and etc.

主要成分：绿茶精华、杏仁油、薄荷、阳离子活性剂、高弹性定型因子等。

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