当您手中的10余条绳子套完之后，就能发现在第一条绳子环扣处的蟹已懒洋洋地趴在洞口了。
O B-Person B-Thing O O B-Metric I-Metric I-Metric I-Metric B-Thing I-Thing O O O O O O O O O O O O O B-Thing I-Thing B-Location I-Location I-Location O B-Thing O O O O O O O B-Location I-Location O O