was closed,大概这个题目是这个意思,主句是过去时,从句表示过去的状态,从句接上was closed ,因为close用物做主语要被动.
原句有可能是：She saw (that) the school gate___ ___ because it was Sunday that day.
不过要是我自己写这句话我肯定写成She saw the school gate colsed because it was Sunday that day.用过去分词closed 做school gate 的后置定语就ok了,不过这么填写句子结构和上面那种做法就不同了.