Question: Besides the length of Charles Grethen's primary race event, which two race lengths are standard in middle-distance running?

Context paragraphs:
Peyman Nasiri Bazanjani: Peyman Nasiri Bazanjani (born 10 June 1980) is a Paralympic athlete from Iran who competes in T20 classification middle-distance running events.  Nasiri Bazanjani represented Iran at the 2012 Summer Paralympics in London, where he won Gold in the 1500 m race.  He is also a two-time winner of the 1,500 m race at the IPC World Championships, in Christchurch in 2011 and in Lyon in 2013.

800 metres: The 800 metres, or 800 meters (US spelling), is a common track running event.  It is the shortest common middle-distance running event.  The 800 metres is run over two laps of the track (400 metre track) and has been an Olympic event since the first games in 1896.  During indoor track season the event is usually run on a 200-metre track, therefore requiring four laps.

Daniel Pek: Daniel Pek (born 28 November 1991) is a Paralympic athlete from Poland who competes in T20 classification middle-distance running events.  Pek represented Poland at the 2012 Summer Paralympics in London, where he won silver in the 1500 m race.  He has also finished on the podium at both World and European Championships, winning the gold medal at the 2016 European Championship in Grosseto in his favoured 1,500m event.

Race engineer: A race engineer is a motorsport team member whose role is to communicate with the data analyst as well as the mechanics to determine the changes to be made to the vehicle.  Off the race track, the race engineer analyzes historical data to determine the initial set up for the next race event.  The race engineer function includes hands-on management of the vehicle mechanics, organizing testing schedule, as well as studying the regulations.  The race engineer seeks to make all these activities occur as seamlessly as possible for their driver.

Middle-distance running: Middle-distance running events are track races longer than sprints, up to 3000 metres.  The standard middle distances are the 800 metres, 1500 metres and mile run, although the 3000 metres may also be classified as a middle-distance event.  The 1500 m came about as a result of running three and 3/4 laps of a 400 m outdoor track or 7 and a half laps of a 200m indoor track, which were commonplace in continental Europe in the 20th century.

Charles Grethen: Charles Grethen (born 2 June 1992 in Tuntange) is a Luxembourgian middle-distance runner competing primarily in the 800 metres.  He represented his country at three consecutive European Championships.

Trenton 150: The Trenton 150 was an American Championship Car race held at Trenton International Speedway from 1946 until 1979.  In most years, two races were held: one in April, and one in September.  Race lengths varied between 100, 150, 200, or 300 miles.  The first four editions were held on a dirt track.

Myrtle Beach 250: The Myrtle Beach 250 was a NASCAR Busch Series stock car race held at Myrtle Beach Speedway, in Myrtle Beach, South Carolina.  Added to the Busch Series schedule in 1988, Myrtle Beach Speedway hosted one race per year through the 2000 season, after which it was removed from the schedule.  The first three races held were 200 laps, covering 107.6 mi .  The distance was extended to 250 laps starting in 1991, where it remained for the rest of the race's history.  Jimmy Spencer and Jeff Green were the only drivers to win twice in this race.  Spencer won at both the 200 and 250 laps race lengths, while Green won the final two races ever held at Myrtle Beach.

Sunny South Raceway: Sunny South Raceway originally opened in 1989 as a 1/8 mile dirt go-kart track in Grand Bay, Alabama.  Full-size cars started running on the track in 1993.  In 1996, the track was expanded to 1/4 mile and later paved in 2002.  Sunny South Raceway has previously been operated under the names Big Oaks Speedway and J & J Speedway.  Today's version of the track is a high-banked 1/4 mile D-shaped paved oval.  It has eighteen degree banking in the corners, twelve degrees on the backstretch, and six degrees on the frontstretch.  The track has previously held races for the Southern All Star Supertruck Series.  Sunny South Raceway holds races for Pro Challenge, INEX Legends and Bandoleros, Go-Karts, Stingers, Bombers, and other types of race cars.  On September 21, 2012, Sunny South Raceway held the INEX Bandolero Nationals, a race that draws over fifty bandolero drivers every year.  The track also hosts the "Memorial Day Classic", a two-day race event held every year at Sunny South Raceway.  The Sunny South Criterium, a professional bicycle race, was held on April 6, 2013 at Sunny South Raceway.  Sunny South Raceway hosted 2013 Pro Challenge National Championship Race on October 4, 2013.  NASCAR drivers such as Cale Gale, Grant Enfinger, Johanna Long, and others have raced at Sunny South Raceway.

Lydia Gurley: Lydia Gurley (born 9 September 1984) is an Irish female track cyclist, representing Ireland at international competitions.  She competed at the 2016 UEC European Track Championships in the points race event, team pursuit event and elimination race event.

Supporting paragraphs: Charles Grethen Middle-distance running
Answer: 1500 metres and mile