parallel-series connection

例句：

1. 1. The parallel-series connection between the two systems is crucial for their synchronization.
   这两个系统的平行系列连接对于它们的同步至关重要。
2. 2. The researcher found a parallel-series connection between the two variables that could be used to predict future trends.
   研究者发现两个变量之间存在一种平行系列联系，可以用来预测未来的发展趋势。
3. 3.The engineer designed a parallel-series connection to improve the efficiency of the power system.
   工程师设计了一种平行系列连接来提高电力系统的效率。