General Dynamics System Engineer interview questions

During the job interview, HR kept asking general questions and some deep questions about position that I applied. I was unpleasant when she asked. The way how she asked and her attitude was not professional. I felt like bully while interview.

- Over the phone Interview - In Person Interview with 3 different interviewers one after another, each for 1hr. - Over the phone 5 Question pop quiz, about C++ Classes: 1- Why does C++ use Name mangling? 2- What is a Pure Virtual Function? 3- What is a pure Virtual Function used for? 4- (Don't remember) 5- (Don't remember)