You could knock me down with a feather.

这... Well...你吹口气我都能倒下。

'You could knock me down with a feather, ' she answered so surprised that she looked at him blankly.

“你可以用一根羽毛把我打倒，”她惊讶地回答，她茫然地看着他。

You could have knocked me down with a feather when I came into the bungalow and saw you sitting down and resting.

当我走进平房看到你坐下来休息时， 你可以用一根羽毛把我打倒。