导游告诉我们，莱茵河只有12个管理人员，由该河保护委员会管理。
B-Person I-Person O O B-Person I-Person O B-Location I-Location I-Location O O B-Metric I-Metric I-Metric B-Person I-Person I-Person I-Person O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O