as plain as the nose on one's face这个俚语字面上的意思就是“像某人脸上的鼻子一样明显”，引申为“显而易见、一清二楚”之意。

【例句】
As plain as the nose in your face, he refused you.
显而易见，他是拒绝你的。

Jack is always trying to butter up the boss. It's as plain as the nose on his face.
Jack 老是想讨好老板。实在是太明显了。