Listening 15. (No. 41~42)
https://www.youtube.com/watch?v=mD4_P4FfUog&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=28
Listening 16. (No. 43~44)
https://www.youtube.com/watch?v=oR7u18S00N8&list=PL6D-YTosvGYq8YexsOG53BGav1CD0t3aM&index=29