风速6min/s是几级风?

风速6min/s是几级风? 风速15m /s是几级风 风速31m/s是几级风? 风速是18m/s 是几级风 风速10M/S是几级风啊 风速10M/S是几级风啊 900s= min 900s＝?min 10s=( )min 20s=( )min E min S 110s=?min 风速里的节和m/s怎么转换?另外6级风＝?m/s = 节 20s等于多少min? 17s等于多少min 20s=（）min 72m/min cm/s s和min差多少?