Q: Information:  - Mactridae, common name the trough shells or duck clams, is a family of saltwater clams, marine bivalve mollusks in the order Veneroida.  - The Atlantic surf clam , also referred to as the `` bar clam , '' `` hen clam , '' `` skimmer , '' or simply as the `` sea clam , '' is a western Atlantic surf clam , a very large ( 20 cm ) , edible , saltwater clam or marine bivalve mollusk in the family Mactridae . It is a much larger relative of the eastern Atlantic surf clam . The shell of this species is a well - known object to beach - goers in the northeastern United States . People on the beach often pick up a large empty shell of this species , either to dig in the sand with , or take home to use as a decorative dish or ashtray . The species is exploited commercially as a food item .  - The surf clam ("Spisula solida", is a medium-sized marine clam, or bivalve mollusc commonly found in the waters surrounding Great Britain. Up to long, it is like many clams a sediment-burrowing filter feeder.  - Great Britain, also known as Britain , is a large island in the north Atlantic Ocean off the northwest coast of continental Europe. With an area of , Great Britain is the largest European island and the ninth-largest in the world. In 2011 the island had a population of about 61 million people, making it the world's third-most populous island after Java in Indonesia and Honshu in Japan. The island of Ireland is situated to the west of it, and together these islands, along with over 1,000 smaller surrounding islands, comprise the British Isles archipelago.  - The Veneroida or veneroids are an order of mostly saltwater but also some freshwater bivalve molluscs. This order includes many familiar groups such as many clams and cockles that are valued for food, and a number of freshwater bivalves including the invasive species of zebra mussels.    What is the relationship between 'atlantic surf clam' and 'spisula'?
A: parent taxon

Q: Information:  - Racewalking, or race walking, is a long-distance discipline within the sport of athletics. Although it is a foot race, it is different from running in that one foot must appear to be in contact with the ground at all times. This is assessed by race judges. Typically held on either roads or on running tracks, common distances vary from 3000 metres (1.8 mi) up to 100 kilometres (62.1 mi).  - The 12th IAAF World Championships in Athletics were held in Berlin, Germany from 1523 August 2009. The majority of events took place in the Olympiastadion, while the marathon and racewalking events started and finished at the Brandenburg Gate.  - Vietnam, officially the Socialist Republic of Vietnam (SRV), is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90.5 million inhabitants , it is the world's 14th-most-populous country, and the eighth-most-populous Asian country. Vietnam is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, Thailand across the Gulf of Thailand to the southwest, and the Philippines, Malaysia and Indonesia across the South China Sea to the east and southeast. Its capital city has been Hanoi since the reunification of North and South Vietnam in 1976.  - Cambodia competes at the 2009 World Championships in Athletics from 15 -- 23 August in Berlin .  - Cambodia (or Kampuchea ), officially known as the Kingdom of Cambodia (Preh Réachéanachâk Kâmpchéa), is a country located in the southern portion of the Indochina Peninsula in Southeast Asia. It is in area, bordered by Thailand to the northwest, Laos to the northeast, Vietnam to the east, and the Gulf of Thailand to the southwest.  - The European Union (EU) is a political and economic union of member states that are located primarily in Europe. It has an area of , and an estimated population of over 510 million. The EU has developed an internal single market through a standardised system of laws that apply in all member states. EU policies aim to ensure the free movement of people, goods, services, and capital within the internal market, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries, and regional development. Within the Schengen Area, passport controls have been abolished. A monetary union was established in 1999 and came into full force in 2002, and is composed of 19 EU member states which use the euro currency.  - Berlin is the capital and the largest city of Germany as well as one of its constituent 16 states. With a population of approximately 3.5 million people, Berlin is the second most populous city proper and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has about 6 million residents from more than 180 nations. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers and lakes.    What is the relationship between 'cambodia at the 2009 world championships in athletics' and '23 august 2009'?
A:
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