上面的句子是表语从句
主语是The last time ,we had great fun 是The last time的定语,was是系动词
下面的句子也是表语从句
What made the school proud 是主语从句,was是系动词,根据主系表的结构,后面必须是表语
同位语从句前面必须有先行词,而且先行词在从句里面不做任何成分.例如：The idea that you can do this work well without thinking is quite wrong.你认为不动脑筋就能做好这件工作同位语从句的想法是完全错误的.that you can do this work well without thinking 就是作idea的同位语,很明显,idea在从句中不做任何成分,也就是说把同位语从句删掉后,还是一个完整句子The idea is quite wrong.