A and B is 还是are？

A and B is 还是are？
请看一下这几个句子：
A and B are students 这肯定是对的了
A and B has还是have the same feeling?
A and B is还是are the same person?
是不是说只要是A and B作主语的情况下，A and B 都可以直接看作是一个复数词也就相当于they？
如果后面所指的是同一个人，或是同一件事物，那A and B 后面是不是要加单数呢？
另外这句话： My telephone nuber and my qq number is还是are the same number？
My telephone and qq,their number is还是are 123456.
My telephone and qq's number is还是are the same one.