Corso Business English SEDAPTA - Telephone English exercises

https://learnenglish.britishcouncil.org/skills/listening/b1-listening/phone-call-customer

https://www.englishclub.com/speaking/telephone.htm

http://usefulenglish.ru/phrases/phrases-exercise-four

http://www.esl-lab.com/eslbasic/telephone-cellphone-1.htm

http://www.bbc.co.uk/worldservice/learningenglish/business/talkingbusiness/unit1telephone/1connecting.shtml

https://www.engvid.com/how-to-start-a-phone-conversation/

https://www.youtube.com/watch?v=NWawMZxDh9Y

https://www.youtube.com/watch?v=YMxA4Q94qao