Lǎo / shī / jiě / shì / shuō / bì / kǒu / yùn / shì / yǐ / shuāng / chún / yīn / shōu / wěi / de / yùn / mǔ

老师解释说，闭口韵是以双唇音收尾的韵母。

The teacher explained that a closed-mouth final is a final ending in a bilabial sound.