blackboard eraser

例句：

1. 1. The teacher uses a blackboard eraser to clean the board before class.
   老师在上课前用黑板擦清理黑板。
2. 2. She used her blackboard eraser to write on the whiteboard.
   她用黑板擦在白板上写字。
3. 3. The student asked for a blackboard eraser so he could correct his mistakes.
   学生请求一块黑板擦，以便他能纠正错误。