tā / zài / jiān / kǔ / de / huán / jìng / zhōng / bù / duàn / shuāi / dǎ / zì / jǐ / zhōng / yú / biàn / de / jiān / qiáng / qǐ / lái

他在艰苦的环境中不断摔打自己，终于变得坚强起来。

He constantly toughened himself through difficult circumstances and eventually became stronger.