只有那给人们生活带来方便的小黑板，仍然挂在社区墙外醒目的位置，几年如一日。
O O O O B-Person I-Person O O O O O O O B-Thing I-Thing I-Thing O O O O O B-Location I-Location I-Location I-Location I-Location I-Location I-Location I-Location I-Location O O O O B-Metric I-Metric O