lǎo / shī / de / yì / fān / pī / píng / gěi / le / tā / dāng / tóu / bàng / hè / ràng / tā / chóng / xīn / rèn / shi / dào / zì / jǐ / de / wèn / tí

老师的一番批评给了他当头棒喝，让他重新认识到自己的问题。

The teacher's criticism was a wake-up call that made him reconsider his problems.