Input: Read this: The Song dynasty reestablished unity around 960. Under the Song, the prosperity of South China began to overtake that of North China. After the north was lost to the Jurchen Jin dynasty in 1127 following the Jingkang Incident, Hangzhou became the capital of the Southern Song under the name Lin'an. Renowned for its prosperity and beauty, it may have been the largest city in the world at the time. From then on, north Zhejiang and neighboring south Jiangsu have been synonymous with luxury and opulence in Chinese culture. The Mongol conquest and the establishment of the Yuan dynasty in 1279 ended Hangzhou's political clout, but its economy continued to prosper. Marco Polo visited the city, which he called "Kinsay" (after the Chinese Jingshi, meaning "Capital City") claiming it was "the finest and noblest city in the world".
Question: Who dissolved in 960?

Output: unanswerable

Input: Read this: Each code point has a single General Category property. The major categories are: Letter, Mark, Number, Punctuation, Symbol, Separator and Other. Within these categories, there are subdivisions. The General Category is not useful for every use, since legacy encodings have used multiple characteristics per single code point. E.g., U+000A <control-000A> Line feed (LF) in ASCII is both a control and a formatting separator; in Unicode the General Category is "Other, Control". Often, other properties must be used to specify the characteristics and behaviour of a code point. The possible General Categories are:
Question: What is the title of the Separator category in Unicode?

Output: unanswerable

Input: Read this: Bill & Melinda Gates Foundation (or the Gates Foundation, abbreviated as BMGF) is the largest private foundation in the world, founded by Bill and Melinda Gates. It was launched in 2000 and is said to be the largest transparently operated private foundation in the world. The primary aims of the foundation are, globally, to enhance healthcare and reduce extreme poverty, and in America, to expand educational opportunities and access to information technology. The foundation, based in Seattle, Washington, is controlled by its three trustees: Bill Gates, Melinda Gates and Warren Buffett. Other principal officers include Co-Chair William H. Gates, Sr. and Chief Executive Officer Susan Desmond-Hellmann.
Question: What are the names of the trustees for the foundation based in America?

Output: unanswerable

Input: Read this: The softness of copper partly explains its high electrical conductivity (59.6106 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 3.1106 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 metal has a higher thermal conductivity than copper?

Output:
silver