lǎo / shī / yòng / pò / zhé / hào / biǎo / shì / zhè / jù / huà / hòu / miàn / hái / yǒu / bǔ / chōng / shuō / míng

老师用破折号表示这句话后面还有补充说明。

The teacher used a dash to show that an additional explanation followed the sentence.