lǎo / shī / xiān / shì / fàn / cháng / yīn / de / fā / yīn / zài / ràng / xué / shēng / liàn / xí / duǎn / yīn

老师先示范长音的发音，再让学生练习短音。

The teacher first demonstrates the pronunciation of long sounds, then has the students practice short sounds.