使用LTspice仿真多路复用器时出现unknown circuit node:"u2:9"requested in behavioral source ,报错说未知电路节点,行为来源中要求的u2:9“。请问是什么情况导致的,要如何解决。 Unknown circuit node appears when using LTspice to simulate a multiplexer: "u2: 9" was requested in the behavior source, an e...