Information: - The Tideway is a name given to the part of the River Thames in England that is subject to tides. This stretch of water is downstream from Teddington Lock and is in its widest definition just under long. The Tideway includes the Thames Estuary, the Thames Gateway and the Pool of London. - The River Severn (Welsh: "Afon Hafren", Latin: "Sabrina") is the longest river in the United Kingdom, at about . It rises at an altitude of on Plynlimon, close to the Ceredigion/Powys border near Llanidloes, in the Cambrian Mountains of mid Wales. It then flows through Shropshire, Worcestershire and Gloucestershire, with the county towns of Shrewsbury, Worcester and Gloucester on its banks. With an average discharge of at Apperley, Gloucestershire, the Severn is the greatest river in terms of water flow in England and Wales. - The River Thames is a river that flows through southern England. At , it is the longest river entirely in England and the second longest in the United Kingdom, after the River Severn. It also flows through Oxford (where it is called Isis), Reading, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. It rises at Thames Head in Gloucestershire, and flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London. - Culham Lock is a lock on the River Thames in England close to Culham, Oxfordshire. It is on a lock cut to the north of the main stream, which approaches the large village of Sutton Courtenay. The lock was built of stone by the Thames Navigation Commission in 1809. - Teddington Lock is a complex of three locks and a weir on the River Thames in England at Ham in south west London. The lock is on the southern side of the river. - Abingdon Bridge crosses the River Thames at the town of Abingdon , Oxfordshire , England . It carries the A415 road from Abingdon to Dorchester , Oxfordshire , over the reach of the Thames between Culham Lock and Abingdon Lock . The bridge is actually two bridges , linked by Nag 's Head Island . Abingdon Bridge is the northern part towards the town which has six arches and crosses the backwater and mill stream . The southern part is technically called Burford Bridge and has one main arch and four minor arches at the river and two minor arches on the floodplain . This crosses the main navigation channel . Furthermore to complete the Thames crossing , Culham Bridge crossing the Swift Ditch should also be considered as an extension . Given the information above, choose from the list below the object entity that exhibits the relation 'material used' with the subject 'abingdon bridge'. Choices: - ham - stone - water
stone

Information: - A sclerite (Greek , ', meaning "hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly to the hardened parts of arthropod exoskeletons and the internal spicules of invertebrates such as certain sponges and soft corals. In paleontology, a scleritome is the complete set of sclerites of an organism, often all that is known from fossil invertebrates. - The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite , and with an allegedly distinctive microstructure . Their skeletons may be homologous to those of the molluscs , and Halkieria looks very much like a polyplacophoran . The shells of this group and the molluscs appear to have originated in the same fashion . However , there are several reasons to doubt this relationship , many of which may not pass muster . There are two groups within the coeloscleritophorans : the Sachitids , to which Halkieria and Wiwaxia belong , and the Chancellorids . The Ediacaran fossil Ausia has been touted as an ancestral ' intermediate ' between both of these groups . These are common constituents of Lower Cambrian small shelly fossil assemblages . - Aragonite is a carbonate mineral, one of the two most common, naturally occurring, crystal forms of calcium carbonate, CaCO (the other form being the mineral calcite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments. - Aragon (or , Spanish and , or ) is an autonomous community in Spain, coextensive with the medieval Kingdom of Aragon. Located in northeastern Spain, the Aragonese autonomous community comprises three provinces (from north to south): Huesca, Zaragoza, and Teruel. Its capital is Zaragoza (also called "Saragossa" in English). The current Statute of Autonomy declares Aragon a "nationality" of Spain. - An exoskeleton (from Greek , "ex" "outer" and , "skeletos" "skeleton") is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton (endoskeleton) of, for example, a human. In usage, some of the larger kinds of exoskeletons are known as "shells". Examples of animals with exoskeletons include insects such as grasshoppers and cockroaches, and crustaceans such as crabs and lobsters. The shells of certain sponges and the various groups of shelled molluscs, including those of snails, clams, tusk shells, chitons and nautilus, are also exoskeletons. Some animals, such as the tortoise, have both an endoskeleton and an exoskeleton. Given the information above, choose from the list below the object entity that exhibits the relation 'parent taxon' with the subject 'coeloscleritophoran'. Choices: - animal - saragossa
animal