Decreasing nationalism is the answer.
They wanted to present them as if they were gods. This was quite common in history and is a reason for example why pharaohs got pyramids built in their honor. The giant heads depicted their leaders as gods or someone who is in general larger than life itself. It was a sign of respect and others who would visit would also see this and know who they are dealing with. Such heads can still be found and examined which is important when trying to understand their ancient culture.
Answer:
In ancient times learned how to obtain copper from the ore by heating the rock to the metal melting point. They used to mould bronze objects by pouring the metal into stone shapes or ingots.
Explanation:
