In my middle-school and highschool science courses, we sat at tables that had gas feeds to them. I don't recall what they were marked - probably oxygen and nitrogen or hydrogen or something. There had barbed ends, so as to connect to a flexible hose.
I never used them. Not once. I never saw them used. They were a feature of hopeful design, or vestigial hands-on activities.
It's much easier to create stability and equity by making sure nobody gets an exceptionally good education than to make sure nobody gets an exceptionally bad one.
I never used them. Not once. I never saw them used. They were a feature of hopeful design, or vestigial hands-on activities.