wèi / le / wán / chéng / zhè / xiàng / yán / jiū / tā / kǔ / xīn / gū / yì / de / zuān / yán / le / shí / duō / nián

为了完成这项研究，他苦心孤诣地钻研了十多年。

To complete this research, he devoted himself painstakingly to it for more than ten years.