他皱了皱眉，不屑地哼了一声。

He frowned and ___sniffed disdainfully.

她很快察觉到了房间里的紧张气氛。

She quickly ___sniffed out the tension in the room.

她不屑地哼了一声，转身离开了房间。

She ___sniffed dismissively and turned to leave the room.