Looks like the Newton boy'sgot a big smile for you. Yeah, he's a good buddy.

VOA: standard.other

If it's a true happiness smile, that's actually bodes better for the relationship than a Pan Am, or greeting smile.

如果是一个真正开心的微笑，对这段感情来说是个好兆头,比问候式微笑好的多。

耶鲁公开课 - 心理学导论课程节选

There is some evidence for a third sort of smile.

有证据表明有第三类微笑。

耶鲁公开课 - 心理学导论课程节选