He drove with blithe disregard for the rules of the road.

　　他開車時全然不顧交通法規。

　　It does so with blithe disregard for best scientific practice.

　　沒有考慮最科學的做法就輕率地這么做了。

　　She said 'hi' with the blithe assurance of someone who knew how much she'd been missed.

　　她高興地說了聲“嗨”，好像確信大家非常想念她似的。

　　Suzanne's feelings about food and eating had gone from blithe unconcern to anxiety.

　　蘇珊娜對飲食的態度已經從無所謂變成了焦慮不安。

　　I made a blithe comment about the fine weather.

　　我隨便說了句天氣很好之類的話。