xué / xí / pǔ / tōng / huà / yùn / mǔ / shí / lǎo / shī / xiān / jiǎng / jiě / qí / chǐ / hū

学习普通话韵母时，老师先讲解齐齿呼。

When studying Mandarin finals, the teacher first explained qichihu.