What was the cultural feature of a large city like Chang’an?

The site of the Han capital was located 3 km northwest of modern Xi'an. As the capital of the Western Han, it was the political, economic and cultural center of China. ... The magical significance of this location was believed to ensure a long-lasting dynasty like the Zhou, whom the Han sought to emulate. i hope that answers your question

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust. 

The correct answer is kettles.