要了解为什么电源插座不一样，你需要知道插头的工作原理。
【原文】
This article about electrical outlets is republished here with permission from The Conversation. This content is shared here because the topic may interest Snopes readers; it does not, however, represent the work of Snopes fact-checkers or editors.
You find yourself in an airport or hotel room in another country, and you really need to charge your phone, camera or game system. But what is that strange-looking outlet? It has round holes! And there are two? Or three? What’s going on here? Why doesn’t this country use the same plugs that I use back home?
The short answer is that the systems that deliver electricity to homes around the world have been built by thousands of people over the last 140 years. And they’re not finished yet. Around the world, about 750 million people – one out of every 10 – still don’t have access to electricity. But for the 90% who do, there are 15 different types of domestic electrical outlet plugs in use around the globe.
The bottom line is that countries might support the idea of a global standard, but no one wants to change theirs. So for the foreseeable future, if you’re getting ready for a trip, don’t forget to pack your adapters.
Theodore J. Kury, Director of Energy Studies, University of Florida
This article is republished from The Conversation under a Creative Commons license. Read the original article.