Listening 3. (No. 9~12)
https://www.youtube.com/watch?v=nLvwtheCKkQ&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=16
Listening 4. (No. 13~16)
https://www.youtube.com/watch?v=NYGrWgPqby4&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=17