She'd mentioned it casually once, surprising him by her unconcern.

她随意地提过一次这个事，她的漠不关心让他吃惊。

She received the news with apparent unconcern.

她接到这消息时显然无动于衷。

Unconcern in his voice.

他的声音漠不关心。

He regards such matter with complete unconcern.

他对这种事情毫不关心。

The opposite of love is not hatred but unconcern.

爱的对立面并不是憎恨，而是漫不经心。