Choose the option that best completes each numbered blank in the passage.

Teenagers (26) __________ take part in community services. These activities have huge benefits. It is obvious that the society benefits from these activities. (27) __________, the old are cared for; the streets are cleaned up; the blood bank has a plentiful supply. In return, those who do community services gain a lot. They have a chance to contact different groups of people. This (28) __________ them precious lessons of communication. They can improve their skills. They (29) __________   how to work in a team. Above all, they learn to share and care for others. In short, community services are (30)_________  and should be part of teenagers’ education.