on open day还是in open day?

on open day还是in open day? 是on the open day还是in the open day on the Open Day 意思 open day 英语作文on the open day on open in open on the open day 是用什么时态写?过去式还是将来时 打开电视机用turn on还是open 电视开着用open还是用on 炉子开着用open还是on 打开水龙头用open还是trun on OPEN open open open open open