Culture. Food, behavior.
History. Common past.
Religion. Majority of shared faith.
Nationality. Belief in common ancestry.
Territory. Boundaries, like Lake Michigan.
Language. Common dialect.
Nation-state. An independent geopolitical unit of people having a common culture and identity.
<span>An increase in scientific and medical discoveries improved life expectancies.
</span>The best possible explanation for the changes in Europe's population since 1750 is that an increase in scientific and medical discoveries improved life expectancies.In fact, it was around this type that basic hygiene norms were implemented, as well as some mortal diseases were cured or to improve lifbetter treated. Moreover, the discovery of vaccinations helped greatly to improve life expectancies.
