Section D 16. What is the purpose of the video library? To help people improve their abilities. 17. What problem may people have when using the library for the first time? They may have difficulties understanding . 18. What are people advised to do when listening to the video? Write down the they hear and understand. 19. What should people do in listening to each conversation? Try to notice the . 20. How can people start watching their first video? All they need to do is to click on the link of .