Lǎo / shī / jiě / shì / shuō / shī / zhōng / de / ěr / cáo / zhǐ / de / shì / dāng / shí / de / nián / qīng / rén

老师解释说，诗中的“尔曹”指的是当时的年轻人。

The teacher explained that “尔曹” in the poem refers to the young people of that time.