A plug is an electric outlet.
插座 • Then Bob spotted the problem - the plug in the wall hadn't been switched on. 然后鲍勃发现了问题——墙上的插座没有打开。
If you plug a hole, you block it with something.
堵; 塞 • Crews are working to plug a major oil leak. 机组人员正在努力堵一个漏油的大洞。