Complex sentence: She paid her fare and sat in an empty seat in the first row of back seats reserved for blacks in the "colored" section, which was near the middle of the bus and directly behind the ten seats reserved for white passengers.
Split into simpler sentences: She paid her fare and sat in an empty seat in the first row of back seats reserved for blacks in the "colored" section. It was near the middle of the bus and directly behind the ten seats reserved for white passengers.