sentence: I want to be an expert in such areas as drilling , exploitation and development of oilfields . That is why I want to get a master 's degree abroad , or a PhD at my university .
modified: I want to be an expert in such areas as drilling , exploitation and development of oilfield , that is why I want to get a master degree abroad , or PhD at my university .
transformation: NOUN:NUM, PUNCT, NOUN:POSS, DET