苦心kǔxīnto take great pains; laborious effort; deep concernHSK 7-9PronunciationkǔxīnExample sentence他苦心经营这家公司二十年了。Tā kǔxīn jīngyíng zhè jiā gōngsī èrshí nián le.He has painstakingly managed this company for twenty years.Read and choose an answerOne fixed sampleExplore a sample