How are countries in the european union linked?
check all that apply.
they have a shared economy.
they have established a common religion.
they have a single shared language.
they allow easy migration.

The correct choices are;

They have a shared economy.

They allow easy migration.

The European Union is a gathering of 28 nations that works as a durable financial and political square. Nineteen of the nations utilize the euro as their official cash. The EU became out of a longing to frame a solitary European political element to end the time of fighting among European nations that finished with World War II and crushed a great part of the mainland. The European Single Market was built up by 12 nations in 1993 to guarantee the purported four opportunities: the development of merchandise, administrations, individuals and cash.  

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place

well, there are a lot of places we get information about earth from. like science classes, websites, books, newspapers, etc.