To teach is to lern.和To eat is to live.什么情况to放在句首

To teach is to lern.和To eat is to live.翻译下 eat to live和live to eat 英语翻译eat to live ,but not live to eat.it is easier to get mon to live is to give To live is to love to live is to die? to live is to give. Eat to live,but not live to eat.什么意思? ' To teach another is to learn yourself to teach is my job live to eat论据 i live to eat