一个句子只有一个主语（当然可以有多个并列主语）和谓语（当然可以有多个并列谓语）
也就是说一个句子只有一个主谓结构。
至于所列的句子中，当然有
从句（从句也有一个主谓结构）
:One thing主 I didn't like定语从句 was
系动词 the slow pace of the talk
表语.
What I liked about the training session主语从句 was系动词 its variety表语.
One thing主 that was cool定语从句 was系动词 that he wanted to pass on real-world experience表语从句
从句也是句子，只不过是充当一个成分。