oil chalk

例句：

1. 1. He used oil chalk to mark the boundaries of his garden.
   他用油灰粉来标记他的花园边界。
2. 2.The teacher asked the students to use oil chalk to write their names on the blackboard.
   老师要求学生们用油灰粉在黑板上写下他们的名字。
3. 3.The painter used oil chalk to create a smooth and even surface for his painting.
   这位画家使用油灰粉为他的画作创造了一个光滑和均匀的表面。