Complex sentence: In 1939 additional buildings became available for the dining hall and domestic science and in 1973 the Lady Julian Building, which had formerly housed the Notre Dame Preparatory School, became part of Notre Dame High School.
Split into simpler sentences: In 1939 additional buildings became available for the dining hall and domestic science. In 1973 the Lady Julian Building, which had formerly housed the Notre Dame Preparatory School, became part of Notre Dame High School.