Complex sentence: Before the German invasion of Poland, she attended the gymnasium in Będzin, which was located in the industrial region of Zagłębie Dąbrowskie in south-western Poland on the border with Germany.
Split into simpler sentences: Before the German invasion of Poland, she attended the gymnasium in Będzin. The city was was located in the industrial region of Zagłębie Dąbrowskie in south-western Poland on the border with Germany.