Complex sentence: First Communion typically takes place at age seven or eight, depending on which country, however adults that have not received their First Communion can go through a separate program (RCIA) to receive this sacrament.
Split into simpler sentences: First Communion typically takes place at age seven or eight, depending on the country. Adults who have not received their First Communion can go through a separate program called the Rite of Christian Initiation of Adults or RCIA to receive this sacrament.