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.
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Question: Passage: Iranian art encompasses many disciplines, including architecture, painting, weaving, pottery, calligraphy, metalworking, and stonemasonry. The Median and Achaemenid empires left a significant classical art scene which remained as basic influences for the art of the later eras. Art of the Parthians was a mixture of Iranian and Hellenistic artworks, with their main motifs being scenes of royal hunting expeditions and investitures. The Sassanid art played a prominent role in the formation of both European and Asian medieval art, which carried forward to the Islamic world, and much of what later became known as Islamic learning, such as philology, literature, jurisprudence, philosophy, medicine, architecture, and science, were of Sassanid basis. Question: The Achaemind Empire along with what other group became the foundation for the art in later Iranian history?

Answer: The Median


Question: 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?

Answer: The softness


Question: Passage: The Eritrean highway system is named according to the road classification. The three levels of classification are: primary (P), secondary (S), and tertiary (T). The lowest level road is tertiary and serves local interests. Typically they are improved earth roads which are occasionally paved. During the wet seasons these roads typically become impassable. The next higher level road is a secondary road and typically is a single-layered asphalt road that connects district capitals together and those to the regional capitals. Roads that are considered primary roads are those that are fully asphalted (throughout their entire length) and in general they carry traffic between all the major towns in Eritrea. Question: How is the Eritrean highway system named?

Answer:
according to the road classification