What is in common with Mongols, White Huns, and the Mughals as well was that all of them were persecuting Buddhists along their conquests on either Europe or Asiatic soil. None of the mentioned civilizations were particularly fond of the buddhistic teachings.
The terracotta is made out of clay so it might feel like hard clay.
There is little soil, and too much sand.
Conference committees operate after the House and the Senate have passed different versions of a bill. Conference committees exist to draft a compromise bill that both houses can accept. Both houses of Congress must eventually pass identical legislation for the bill to be presented to the President.