I shared one of DC comics' "published as a public service" one-pagers here in the course of talking about the Justice League, but this one here is an even better example than Snapper Carr of the way DC presented "teen-agers" in the 1960s:
From the Brave and the Bold №58, published at the new year 1965, it shows Superboy helping the teen-age population of Smallville plan a community event that will really let everyone get hep to the rules! Because that is of course what sixties teens were all about!
You can tell they're teenagers because one of the boys isn't even wearing a tie! He's probably the most outrageously modern of the group, and he'll probably learn a valuable lesson about conformity soon enough. At least they're all fully aware of the problem of spontaneous combustion of oily rags, now that Superboy's hammered the point home so effectively.
Mind you, Superboy's presence makes me wonder if this is really the sixties anyway - he is, after all, "Superman when he was a boy", which in the contemporary Superboy comics was depicted as non-specifically pre-war kind of surroundings (sixties Superman was generally depicted as middle-aged, unlike the modern insistence that he's under thirty). So maybe these teens are 1930s kids who are very much ahead of their time in terms of clothing and lingo!
In any case, please seal your oily rags away carefully and tell all your friends to obey the rules!