铭心刻骨 | míng xīn kè gǔ | engraved in one's heart and carved in one's bones (idiom) / to remember a benefactor as long as one lives / undying gratitude | |
铭心镂骨 | míng xīn lòu gǔ | engraved in one's heart and carved in one's bones (idiom) / to remember a benefactor as long as one lives / undying gratitude | |
没齿难忘 | mò chǐ nán wàng | hard to forget even after one's teeth fall out (idiom) / to remember a benefactor as long as one lives / undying gratitude |