17) https://drive.google.com/file/d/1Tts9djRqRhE_EMbAImGYmlnmBhD-yrFf/view?usp=sharing
18) https://drive.google.com/file/d/1n4nYob8RjY6W9ZYE_88iX4JUc2VwQNuC/view?usp=sharing