lǎo shī / yòng / bái sè / fěn bǐ / zài / hēi bǎn / shàng / xiě xià / jīn tiān / de / zhòng diǎn

老师用白色粉笔在黑板上写下今天的重点。

The teacher used white chalk to write the key points for today on the blackboard.