The announcement came as the effects of the longest shutdown in American history were spreading across the nation.

特朗普此次宣布停摆时，美国史上最长的政府停摆已产生了巨大影响，遍及全国。

The most dramatic instances of this spreading effect were witnessed in western municipalities such as San Jose and San Diego whose city charters defined their territory over several hundred square kilometers.

西部诸如圣何塞和圣地亚哥这样的自治市是土地扩展最为显著的例证，这两个城市的宪章规定其领域超过几百平方英里。

The key feature of a tragedy of the commons is that it provides an opportunity for an individual to benefit him or herself while spreading out any negative effects across the larger population.

公地悲剧的关键特征是，它为个人提供了一个让他或她自己受益的机会，同时将任何负面影响分散到更多的人群中。