Leave the door open:

不排除任何可能性

(to consider an idea, to allow some new situation to happen)

例句：   

Rick haven't decided on whether or not to get married in the spring or the summer; they're also leaving the door open to a wedding in the fall.

Rick還沒(méi)決定春天還是夏天結(jié)婚，但也不排除會(huì)在秋天結(jié)婚。

Off the wall:

從墻上掉下來(lái) ×

荒誕的；瘋狂的 √

例句：

Our neighbor is an artist. He's a little off the wall, but everyone likes him.

我的鄰居是一個(gè)藝術(shù)家。雖然他有點(diǎn)古怪，但是每個(gè)人都喜歡他。

On the house