正确答案为选项D，与其相关的录音内容是the Swiss government is planning new immigration quotas after a referendum saw a hair’s-breadth majority approve measures on immigration restrictions，意思是瑞士政府正在计划实行新的移民限额，在此前的一次全民公投中以微弱优势通过了对移民进行限制的相关条例。其中的微弱优势用hair’s - breadth majority来表示，与选项D 中的small-margin approve意思对应，都是以微弱优势投票通过。选项A 说瑞士是第28 个加入欧盟的国家，而录音内容的意思是瑞士不是28 个欧盟成员国家之一。选项B 说欧盟是瑞士最重要的经济伙伴，而录音说的是瑞士与欧盟的经济伙伴国有数十年的结约关系。选项C 说瑞士人有自由渠道进入欧盟劳动力市场，而录音与此相关的意思是瑞士与欧盟成员国的长期结约包括一个给予欧盟公民自由进入瑞士劳动力市场的协定。

[重点难点]
理解small-margin与 a hair’s-breadth的语义关联，区分事件主体。

[录音原文]
Switzerland is not in the 28-nation European Union, but has decades-old treaties with its economic partner. They include a deal giving EU citizens free access to Switzerland’s labor market. However, the Swiss government is planning new immigration quotas after a referendum saw a hair’s-breadth majority approve measures on immigration restrictions.