The flame went out in a puff of gray smoke.

VOA: special.2010.05.01

It's called gray matter but that's just because it's out of the head.

叫做灰质,但那只是因为它离开了头颅

耶鲁公开课 - 心理学导论课程节选

It's gray when you take it out of the head.

当你把它从头颅中取出的时候,它就变成了灰色

耶鲁公开课 - 心理学导论课程节选

A large fire then broke out, engulfing several shops and spewing a cloud of gray smoke over the area.

VOA: standard.2009.10.28