laser bar

例句：

1. 1. The laser bar was used to highlight important points during the presentation.
   激光棒在演讲中用于突出重点。
2. 2. The teacher demonstrated how to use the laser bar for a class demonstration.
   老师演示了如何使用激光棒进行班级展示。
3. 3. Students were asked to demonstrate their understanding of the material using the laser bar.
   学生被要求使用激光棒来展示他们对材料的理解。