The Agricultural Revolution was a time of transition between hunting and gathering to the domestication of plants and animals, so there were no "cities" in the traditional sense. The benefit of farming, however, was that you could raise enough crops to feed your family and to trade and/or sell.
Yes, just like in every other century since the invention of employment.
In 1973, OPEC created a major oil crisis in Western European nations and the United States by declaring an embargo against them. The shortage of fuel disrupted businesses and limited the use of cars and other vehicles.
This examples shows interdependence because the US economy was negatively effected by the economic sanctions placed on them by countries who were part of OPEC. This resulted in long gas lines in the US, as well as limits on how much gas individuals could buy at one time.
