leave the door open字面意思：让门开着；引申意思：保留可能性

【例句】
I think we should leave the door open，it's boiling in there.
我觉得我们应该把大门敞着，屋里太热了。

They will leave the door open to taxpayer bail-outs.
他们将保留纳税人纾困的可能性。