of mark

例句：

1. 1.The artist drew a line on the canvas to indicate the beginning of his painting.
   艺术家在画布上画了一条线，以指示他绘画的开始。
2. 2. The policeman used a red flag as a mark to warn drivers to slow down.
   警察使用一面红旗作为标记，来警告司机减速。
3. 3.The company has issued a new logo as a mark of its commitment to sustainability.
   公司已经发布了一个新的标志，作为其对可持续性承诺的象征。