blithely

她愉快地哼着歌在花园里浇花。

She sang ___blithely while watering the flowers in the garden.

他轻松愉快地吹着口哨走过危险区域。

He whistled ___blithely as he walked through the dangerous area.

他毫不在意地吹着口哨走过危险区域。

He walked through the dangerous area ___blithely whistling a tune.