i don't know why he looked worry all day long.________

i don't know why he looked worry all day long.________
i don't know why he looked worry all day long.________

i don't know why he looked worry all day long.________
worry-> worried
look 显得怎么样后面加adj.（形容词）
worry是动词,形容词表示“担心的”是worried

I don't know why he looked worry all day long.
look后要用形容词
worry
n. 1. 烦恼, 忧虑2. 令人忧伤的人[事]
vt. & vi. 1. 担心, 为…发愁2. (使)困扰, (使)烦恼
vt. 1. 骚扰；烦扰；使不安宁2. (狗)攻击，撕咬（动物，尤指羊）

i don't know why he looks worry all day long