Watch the following videos:
Video # 1: https://www.youtube.com/watch?v=ovEZkBLhfz0
Video # 2: https://www.youtube.com/watch?v=g9hb1j_uvqI
Video # 3: https://www.youtube.com/watch?v=-XPbfsl3WGo
Video # 4: https://www.youtube.com/watch?v=06jncswJ4aQ
What did you learn from the Video #1?
What did you learn from Video #2?
What did you learn from Video #3?
What did you learn from Video #4?