Unless your topic is very grim, a smile can be a very powerful thing.

除非您的话题非常严肃，否则保持微笑是非常非常有好处的。

youdao

Unless your topic is very grim, a smile can be a very powerful thing.

除非您的话题非常严肃，否则保持微笑是非常非常有好处的。

youdao