C# Basic Interface question

I'm just starting to learn about interfaces in C# and I have a question. From what I read, the technique of multiple inheritance can be emulated through interfaces. I know how to create an interface. What I'm having trouble with is this. Let's say I have two different classes with methods already defined in them. I use those two different classes from time to time and they work well. They are base classes and are not being inherited from anywhere else (though they could be). Now I want to create another new class, and inherit both of those methods in this new class. Can that be done some how through interfaces? Thanks!

Here is a better understanding of C# Interfaces.

Thanks for your response. However, I've already seen that page and it doesn't answer my original question.