walk的形容詞形式是什么

　　I save on fares by walking to work.

　　我步行上班，可以省車(chē)錢(qián)。

　　Conditions were perfect for walking.

　　那是散步最理想的環(huán)境。

　　He was walking around with a sad face.

　　他四處走著，面帶哀傷。