Complex sentence: The 1973 U.S. Open was the 73rd U.S. Open, held June 14--17 at Oakmont Country Club in Oakmont, Pennsylvania, a suburb northeast of Pittsburgh.
Split into simpler sentences: The 1973 U.S. Open was the 73rd U.S. Open. The golf tournament was held June 14--17,1973, at Oakmont Country Club in Oakmont, Pennsylvania, a suburb northeast of Pittsburgh.