What effect did the Battle of Midway have on the events of World War II? - 3470335
For example, in Tibet, sticking your tongue out functions both as a greeting and a sign of respect. In sharp contrast, as noted by Laurie Patsalides and others, the Maori People of New Zealand have historically used this gesture as part of a war chant preceding battle.
Temporary staining of your tongue will clear up once you stop using whatever product is causing the blackening of your tongue. Fungus or bacteria on your tongue that turn it black will also clear up with time if you practice improved oral hygiene.