Suppose The Eurozone is a monetary union of 19 of the 27 European Union (EU) member states which have adopted the euro (€) as their common currency and sole legal tender. The monetary authority of the eurozone is the Eurosystem. The member states of the EU that have not adopted the euro are 8 of the 27 EU countries.
Can we infer that "All EU member states have adopted the euro as their common currency."? Yes, no, or maybe?