上课时，我看到老师们擦黑板时，因黑板太高了，不仅擦得很费力，还在无意中吸入不少粉笔灰。长此下去，必然影响老师们的身体健康。我看在眼里，急在心里，一直在想，怎样帮老师解决这个难题。 一天早晨，妈妈要我去阳台上晒衣服，来到阳台上，刚举起撑杆，给黑板擦安 In class, I saw that when the teachers wiped the blackboard, the blackboard was too tall. Not only was it very hard to clean up, it also inadvertently inhaled a lot of chalk dust. If things go on like this, they will definitely affect the health of teachers. I look in the eyes, anxious in my heart, has been thinking, how to help teachers solve this problem. One morning, my mother asked me to go to the balcony clothes, came to the balcony, just lift the pole, to the blackboard rub