“10-20 system (swimming safety)”的意思、由来-开放百科全书

词条	10-20 system (swimming safety)
释义	> 20_system {{R to section}}
随便看	Self-murder Self-Murder Self-mutilation Self mutilation Selfmutilation Self (novel) Self number Self-number Self-objectification Self organisation Self-organisation Self-organised criticality Self-organising map Self-organising system Self-organising systems Self-organization Self organization Self-organization system Self-organization systems Self-organize Self organize Self-organized criticality Self organizing Self-organizing Self-organizing map

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。