护照权利排名，美国才第四？哪个国家的护照最给力？

World's best and worst passports revealed frontier /frʌn'tɪr/ n. 前沿；边界；国境 CET4 potential / pə'tɛnʃl / n. 潜能；可能性 CET4 territory / 'tɛrətɔri / n. 领土，领域； CET4 compile / kəm'paɪl / v. 编译；编制 CET6 unencumbered / ,ʌnɪn'kʌmbɚd / adj. 没有阻碍的 clout / klaʊt / n. 破布；敲打，影响力TEM4 When it comes to crossing international frontiers, there's one travel document that opens more doors than any other. And it isn't a U.S. passport. German citizens, it seems, have the potential for the greatest mobility in the travel world. With a German passport, travelers can enter 177 out of 218 countries and territories without a visa, according to the 2016 Visa Restrictions Index. The list, compiled annually since 2006 by London-based consulting firm Henley and Partners and the International Air Transport Association, ranks natio ns by how freely their citizens, unencumbered by immigration red tape, can explore the planet. This year, it shows that citizenship of a superpower doesn't carry the clout it once did. The United States, which ranked first in 2014 and 2015, has now dropped to fourth place. At the bottom of the list, labeled countries with the "worst passports," are Afghanistan, at 104, followed by Pakistan, Iraq, Somalia, and Syria.