change-over switch

例句：

1. 1. The engineer changedthe over switch to make the machine workbetter.
   工程师把换向开关换了，使机器工作得更好。
2. 2. Theold man used to operatea switchboard in his factory.
   那位老人以前在工厂里操作过一个交换机。
3. 3. The technician replaced the faulty switch and tested it to ensure itworked properly.
   技术员更换了故障的开关并测试了一下，确保它正常工作。