nonchalantly

The cat nonchalantly groomed its fur while the dog barked at it through the window.

(Chinese) 当狗隔着窗户对猫吠叫时，猫正漫不经心地梳理着羽毛。

He walked nonchalantly into the room and sat down, ignoring the angry looks from his boss.

(Chinese) 他漫不经心地走进房间坐下，无视老板那愤怒的目光。