Which development facilitated twenty-four hour factory operations, skyscraper construction, and mass transportation out of the inner city?
O Electric power
O Steam Engines
O The oil industry
O The steel industry

O Steam Engines

Explanation:

The steam engines is the development that facilitated 24 hours factory operations, skyscraper construction and mass transportation out of the city. This is because, the steam engine, is used to power the machines used in those industries. And, also, it powers the locomotives used in train as a means of transporting people from one point in the city to another location.

this means that germany had to pay the allied countries. reparations are/is essentially payment for something that they have done wrong, so after ww1, germany was forced to pay reparations so they could replenish the allied countries resources' that they had lost during the war.