英语应该不是这样用的吧
Stand alone是孤立没错
不过Complex作为名词是指
1. a group of buildings or one large building used for particular purpose (一群建筑物或者一个大建筑物为了某个特定而使用,比如像Shopping Center or Mall)
2. an emotional problem in which someone is too anxious about something or thinks too much about it (因为过于考虑而导致的情绪上的不安)
从Dictionary.com上找到的
我觉得Complicated比较合适,因为同样表达复杂而且可以当副词用,Complex不能变做副词用。