黑板擦干净了.The blackboard has been wiped clean.老师建议我们课后把黑板擦了.The teacher suggested that we ( should ) clean the blackboard after class.你可以用黑板擦把粉笔印擦掉.You can rub out the chalk marks with the eraser....

“黑板擦”的英语可以翻译为：lackboard eraser ...