你永远无法知道哪一朵花落在你的头上，为你盛开，而哪一朵花落在你脚边，被你踩碎。
B-Person O O O O O O O B-Metric I-Metric B-Thing O O B-Location I-Location B-Thing B-Location O O B-Person O O O O O B-Metric I-Metric B-Thing O O B-Location I-Location I-Location O O B-Person I-Person O O