yǔ yīn kè shàng / lǎo shī / ràng / wǒ men / bǐ jiào / bù tóng / yǔ yán / zhōng / de / mó cā yīn语音课上,老师让我们比较不同语言中的摩擦音。In phonetics class, the teacher asked us to compare fricatives in different languages.