walk的名詞形式

　　We spent a week walking in the mountains.

　　我們在群山中走了一個星期。

　　I met him by chance out walking yesterday.

　　昨天出去散步時我無意中遇到了他。

　　You must be hungry after all that walking.

　　走了這么遠的路，你一定餓了吧。