Which feature of modern-day societies was a characteristic of all early civilizations? 2.
A. police forces
B. school systems
C. trade organizations
D. religious institutions

D Religion

Explanation:

This was a hard one. All societies had some sort of law, but prehistorically early civilizations did not have this

School systems wasn't needed

It's either C or D,

Religion was an important foundation of every civilization but trade was also very important, I would go with religion.

Actually it was first used in Spain during the Spanish Civil War.  The bombing operations were carried out by the German Condor Legion against the Republican Infantry Legion.  Later on the Germans used carpet bombing as part of their invasion in Europe.  Later on the Allies would also employ carpet bombing on the Germans and later on the Japanese. Today the use of carpet bombing is now considered a war crime as it leaves many people dead or wounded as well as the destruction of buildings and homes.