What is the purpose of this structure? to protect from roman merchants to protect from northern barbarians to make trade along the silk road easier to be a residence for the chinese emperor

they both built pyramids.

the outcome of 1970 oil crisis in united states was that, they began to search ways on how to reduce oil.

in 1970 was a period when there were energy and oil crisis. those who were major centers for industrialization were forced to keep way from supplying of petroleum.

some of the result of this crisis was economic growth became stagnant because prices of oil surged.

due to the increased prices some countries like mexico and norway benefited.