Another interview

Here is what I was asked

1. what is virtual inheritance?
2. what is a singleton?
3. what is a factory?
4. why would you use the virtual key word on a function?
5. what is explicit?(only useful for constructors with a single parameter)
6. how would you reduce disc access in a program?
7. difference between struct and class in C++ , in C#?

and some other questions that I forget.

Appearantly I have to go to a second none technical interview with them, and if I don't screw up, I'll get this job. The interviewer said they do an intensive background check, including checking your credit! Hopefully, these guys aren't flakes like threewave software who ask for your references, check them, ask for your salary expectations, and then don't give an offer.