Group 1 - The core function of currency is to facilitate the exchange of goods and services, evolving from barter systems to a widely accepted medium of exchange [4][5] - The unification of currency in ancient China, initiated by Emperor Qin Shi Huang, laid a solid foundation for economic exchange and highlighted the importance of currency as a symbol of national strength [5] - The evolution of currency into more convenient forms like paper money and coins has made transactions easier and more efficient [7] Group 2 - The U.S. dollar dominates international trade as the primary settlement currency due to the significant influence of the U.S. economy, with exchange rates reflecting the relative economic strength of countries [9] - A country's currency issuance affects its exchange rate; excessive printing can lead to devaluation, impacting purchasing power and international standing [10] - The Chinese yuan (RMB) has become the fourth most circulated currency globally, symbolizing China's economic strength and increasing influence in international markets [11][12]