洪炉

zhàn zhēng de hóng lú

战争的洪炉

crucible of war

zài gé mìng de hóng lú li duàn liàn

在革命的洪炉里锻炼

be tempered in the mighty furnace of revolution

xué xiào shì táo yě qīng nián de hóng lú

学校是陶冶青年的洪炉。

School is the melting pot of youth.