lǎo / shī / jiǎng / kè / yào / yán / bù / fán / xué / shēng / men / dōu / tīng / de / hěn / qīng / chǔ

老师讲课要言不烦，学生们都听得很清楚。

The teacher explained the lesson succinctly, and the students understood it clearly.