Direct Questions

Please watch the video on Audio Boards and Audio (A1) Video https://youtu.be/fBj-x7M_zaw  Answer the following questions

What did the presenter say were the two most difficult jobs in the control room? What did the presenter say "mono" meant? What did he say was the definition of "stereo"?

Please watch the video on Video Switcher and Technical Directing Video https://youtu.be/YNgZY6zu7jw

Answer the following questions What is IFB?

Who can interrupt it? 

(Please Answer the questions directly with no makeups.)