Money is not universal in every country. For example, China uses RMB, the United States uses US dollars, Japan uses Japanese yen and Thailand uses Thai baht. Gold is used as the common currency of commerce between countries, and gold is used in commercial transactions. But there is one exception, because gold is also very heavy and the United States is very strong, so transactions between countries also use dollars. Individuals spending abroad must use the currency of other countries. For example, if you go to Japan, you will use Japanese yen when you arrive in Japan. What should I do? Go to the Bank of China and change RMB into Japanese yen. The Bank of China will reserve some foreign currency for your convenience.