Complex sentence: It is no surprise that PKK in the late 1970s chose the communist-socialist ideology with the rise in urban population in the region, particularly among the young people of the region that had to leave traditional culture to fit to the newly developing industrial urban life.
Split into simpler sentences: It is no surprise that PKK in the late 1970s choose the communist-socialist ideology with the rise in urban population in the region. Specially among the young people of the region that had to leave traditional culture to fit to the newly developing industrial urban life.