laser pointer

例句：

1. 1. The laser pointer is a useful tool for pointing things in the dark.
   激光指针是一个在黑暗中指东西有用的工具。
2. 2. The teacher used the laser pointer to demonstrate the concept of light.
   老师使用激光指针来演示光的概念。
3. 3. The student pointed out the error with the laser pointer.
   学生用激光指针指出了错误。