tā / zài / rǎn chǎng / gōng zuò / le / èr shí nián / duì / rǎn sè / gōng yì / fēi cháng / shú xī

他在染厂工作了二十年，对染色工艺非常熟悉。

He has worked in the dye factory for twenty years and is very familiar with the dyeing process.