Peter is a good student except that he is sometimes careless.Peter is a good student 是主语?

题目

Peter is a good student except that he is sometimes careless.Peter is a good student 是主语?
是个复合句吗？

答案

是主从复合句.
Peter主语 is系动词 a good student表语 except that he is sometimes careless状语从句
其中的except that 是从属连词