Extract the answer to the question from the following context. Question: 1,000 kg Context: Copper is synthesized in massive stars and is present in the Earth's crust at a concentration of about 50 parts per million (ppm), where it occurs as native copper or in minerals such as the copper sulfides chalcopyrite and chalcocite, the copper carbonates azurite and malachite, and the copper(I) oxide mineral cuprite. The largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal, with the largest described single crystal measuring 4.43.23.2 cm.
Ans: tonnes

Extract the answer to the question from the following context. Question: What makes the city significant? Context: New York City is located on one of the world's largest natural harbors, and the boroughs of Manhattan and Staten Island are (primarily) coterminous with islands of the same names, while Queens and Brooklyn are located at the west end of the larger Long Island, and The Bronx is located at the southern tip of New York State's mainland. This situation of boroughs separated by water led to the development of an extensive infrastructure of bridges and tunnels. Nearly all of the city's major bridges and tunnels are notable, and several have broken or set records.
Ans: Nearly all of the city's major bridges and tunnels are notable, and several have broken or set records

Extract the answer to the question from the following context. Question: Which of the following did the Truth and Reconciliation Commision NOT address: the causes of the civil war, Liberian history, or the crimes of the civil war? Context: The subsequent 2005 elections were internationally regarded as the most free and fair in Liberian history. Ellen Johnson Sirleaf, a Harvard-trained economist and former Minister of Finance, was elected as the first female president in Africa. Upon her inauguration, Sirleaf requested the extradition of Taylor from Nigeria and transferred him to the SCSL for trial in The Hague. In 2006, the government established a Truth and Reconciliation Commission to address the causes and crimes of the civil war.
Ans: Liberian history

Extract the answer to the question from the following context. Question: Why might a mixed race native American need to be officially adopted? Context: The social identity of the children was strongly determined by the tribe's kinship system. Among the matrilineal tribes of the Southeast, the mixed-race children generally were accepted as and identified as Indian, as they gained their social status from their mother's clans and tribes, and often grew up with their mothers and their male relatives. By contrast, among the patrilineal Omaha, for example, the child of a white man and Omaha woman was considered "white"; such mixed-race children and their mothers would be protected, but the children could formally belong to the tribe as members only if adopted by a man.
Ans: the child of a white man and Omaha woman was considered "white"