美国First-class forever邮票：核心价值和实用价值

“Justice, Equality, Freedom & Liberty”代表核心价值。

每枚邮票上都有“Forever”，很有实用性。

Non-denominated postage

http://en.wikipedia.org/wiki/Non-denominated_postage

Forever stamps

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对我来说，如何区别“Freedom”和“Liberty”仍然是很困难的事情。

http://dictionary.reference.com/browse/freedom

freedom

noun

1.

the state of being free or at liberty rather than in confinement or under physical restraint: He won his freedom after a retrial.

2.

exemption from external control, interference, regulation, etc.

3.

the power to determine action without restraint.

4.

political or national independence.

5.

personal liberty, as opposed to bondage or slavery: a slave who bought his freedom.

Origin:
before 900; Middle English fredom, Old English frēodōm. See free, -dom

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http://dictionary.reference.com/browse/liberty?s=t

liberty

noun, plurallib·er·ties.

1.

freedom from arbitrary or despotic government or control.

2.

freedom from external or foreign rule; independence.

3.

freedom from control, interference, obligation, restriction, hampering conditions, etc.;power or right of doing, thinking, speaking, etc., according to choice.

4.

freedom from captivity, confinement, or physical restraint: The prisoner soon regained his liberty.

5.

permission granted to a sailor, especially in the navy, to go ashore.

Origin:
1325–75; Middle English liberte < Middle French < Latin lībertās,equivalent to līber free + -tās -ty²

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