The 12 new member states that joined the EU in 2004 and 2007 committed themselves to its adoption, but with no set date. Expansion of the euro zone has therefore been slow, especially in central and eastern Europe, where to date only Slovenia (2007) and Slovakia (2009) have become members of the single currency.
第三，欧元问题。分别在2004和2007年加入欧盟的12个新成员国都承诺要采用欧元，但却没有订立一个时限。欧元区的扩张速度因而放缓，尤其是在中东欧地区，至今只有斯洛文尼亚和斯洛伐克（分别在2007和2009年）成为这个单一货币体系的一员。