smell过去式是什么写

　　The rain had cleared the air, and the grass smelt fresh and sweet.

　　雨水净化了空气，青草闻起来清新芳香。

　　The dogs were smelling round; perhaps they smelt the thief.

　　那些狗在到处嗅，也许它们嗅到了小偷的气味。

　　I smelt the fragrance of it.

　　我闻到了它的香味。