Answer:
exchange rate: the difference in value between two currencies
fluctuate: to be in a constant state of change
currency: government-issued money
Euro: monetary unit shared by several nations in Western Europe
Explanation: A currency is a government issued money in different forms used as a medium of exchange such as bank notes and coins by different countries. Every country or nation has its own currency. It is also a monetary unit that is used commonly by people in a country.
There is the United State Dollar used in the US, the Chinese Yuan, British Pounds Sterling, Canadian Dollar, Australian Dollar, Japanese Yen, Euro used in Europe etc. These are a few examples of currencies used by different nations and countries. These currencies are store values of the nation and are used for trading between different countries in foreign exchange markets at different exchange rates.