Listening 5. (No. 15~16)
https://www.youtube.com/watch?v=GzONXhuzrGE&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=35
Listening 6. (No. 17~18)
https://www.youtube.com/watch?v=79knUJNQrKM&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=36