This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Q: Passage: The softness of copper partly explains its high electrical conductivity (59.6×106 S/m) and thus also high thermal conductivity, which are the second highest (to silver) among pure metals at room temperature. This is because the resistivity to electron transport in metals at room temperature mostly originates from scattering of electrons on thermal vibrations of the lattice, which are relatively weak for a soft metal. The maximum permissible current density of copper in open air is approximately 3.1×106 A/m2 of cross-sectional area, above which it begins to heat excessively. As with other metals, if copper is placed against another metal, galvanic corrosion will occur. Question: What is the explanation for copper's capacity for electrical conductivity?

A: The softness
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Q: Passage: After a new wave of UN sanctions, on 11 March 2013, North Korea claimed that it had invalidated the 1953 armistice. On 13 March 2013, North Korea confirmed it ended the 1953 Armistice and declared North Korea "is not restrained by the North-South declaration on non-aggression". On 30 March 2013, North Korea stated that it had entered a "state of war" with South Korea and declared that "The long-standing situation of the Korean peninsula being neither at peace nor at war is finally over". Speaking on 4 April 2013, the U.S. Secretary of Defense, Chuck Hagel, informed the press that Pyongyang had "formally informed" the Pentagon that it had "ratified" the potential usage of a nuclear weapon against South Korea, Japan and the United States of America, including Guam and Hawaii. Hagel also stated that the United States would deploy the Terminal High Altitude Area Defense anti-ballistic missile system to Guam, because of a credible and realistic nuclear threat from North Korea. Question: How does the United States view North Korea's threats? 

A: credible and realistic nuclear threat
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Q: Passage: Both Rousseau and Locke's social contract theories rest on the presupposition of natural rights, which are not a result of law or custom, but are things that all men have in pre-political societies, and are therefore universal and inalienable. The most famous natural right formulation comes from John Locke in his Second Treatise, when he introduces the state of nature. For Locke the law of nature is grounded on mutual security, or the idea that one cannot infringe on another's natural rights, as every man is equal and has the same inalienable rights. These natural rights include perfect equality and freedom, and the right to preserve life and property. Locke also argued against slavery on the basis that enslaving yourself goes against the law of nature; you cannot surrender your own rights, your freedom is absolute and no one can take it from you. Additionally, Locke argues that one person cannot enslave another because it is morally reprehensible, although he introduces a caveat by saying that enslavement of a lawful captive in time of war would not go against one's natural rights. Question: Why did John Locke believe that one person cannot enslave another?

A:
because it is morally reprehensible
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