sentence: I have taken part in a volunteer programme , looking after children 6 - 12 during the school term , and therefore , I consider myself as having good knowledge of children 's behaviour , which might be useful for the summer camp .
modified: I have taken part in a volunteer programme , looking after children 6 - 12 during the school term , and therefore I consider myself as having a good knowledge of children 's behaviour , that might be useful for the summer camp .
transformation: PUNCT, DET, DET