National currencies will be completely replaced by the euro in within six months after the introduction of euro notes and coins.
Once countries are a part of the EU, it will be nearly impossible to leave. 
( z1 possible :polarity - :ARG1 ( z2 leave :ARG0 ( z3 country ) ) :degree ( z4 near ) :time ( z5 participate :ARG0 z3 :ARG1 ( z6 organization :name ( z7 name :op "EU" ) ) ) )