3~5章 55:20 PPT https://drive.google.com/file/d/1HwpylSupConoHRTH_0D9VCziTgfPUiVI/view?usp=sharing 6章 1:04:54 PPT https://drive.google.com/file/d/1_UOr94L75NN78OD1jDmJT1tTJ3s5Y6Ak/view?usp=sharing