BETLAB interview questions

The interview was two stage: 1. Pre-screening via phone 2. One to one interview. For the first stage its were simple questions for about 15 minutes. On the second stage, there were two interviewers which asks technical questions from different aspects of .NET platform, OOP, C# language. The interviewers not only asks questions but give some additional info when you're stuck, even they gave me book titles where to read some topics I was not good enough