❶be polished again and again; be revised and rewritten many times; be a finished product;
❷have gone through fire and water; be thoroughly tempered (/steeled); well-experienced; well-seasoned
❍ 他的文章经过～，无须作任何改动。His article has been polished again and again. There’s no need to make any altenation.
❍ 你放心吧，咱们的人都是～的铁汉子，会杀败官兵的。(姚雪垠《李自成》Ⅰ—170) Don’t worry. All our men are tried and tested. They’ll rout the enemy.
千锤百炼
❶steeled and tempered
❷be polished again and again;highly finished
～的老红军战士 tempered (or seasoned)Red Army soldier /～的好文章repeatedly-polished good article
千锤百炼qiān chuí bǎi liàn
比喻人经历多次艰难险阻的锻炼和考验；也比喻文章经过反复、细致的修改。thoroughly tempered, well-experienced, be a finished product