Question: Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology. While uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons, uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors, and produces the fissile material for nuclear weapons. Depleted uranium (238U) is used in kinetic energy penetrators and armor plating.
Is there an answer to this question: What is 239U?

Answer: unanswerable


Question: Muhammad also ordered another siege on the Banu Qurayza during the Invasion of Banu Qurayza, because according to Muslim tradition he had been ordered to do so by the angel Gabriel. Al-Waqidi claims Muhammad had a treaty with the tribe which was torn apart. Stillman and Watt deny the authenticity of al-Waqidi. Al-Waqidi has been frequently criticized by Muslim writers, who claim that he is unreliable. 600-900 members of the Banu Qurayza were beheaded after they surrendered (according to Tabari and Ibn Hisham). Another source says all Males and 1 woman beheaded (according to Sunni Hadith). Two Muslims were killed
Is there an answer to this question: How many Muslims were killed during the invasion of Banu Qurayza?

Answer: Two


Question: The first department stores Lane Crawford was opened in 1850 by Scots Thomas Ash Lane and Ninian Crawford on Des Voeux Road, Hong Kong Island. At the beginning, the store mainly catered visiting ships' crews as well as British Navy staff and their families. In 1900, the first ethnic-Chinese owned Sincere Department Store was opened by Ma Ying Piu, who returned from Australia and inspired by David Jones. In 1907, another former Hong Kong expatriate in Australia, the Kwok's family, returned to Hong Kong and founded Wing On.
Is there an answer to this question: What year did Lane Crawford open? 

Answer: 1850


Question: In order to qualify for protection, a work must be an expression with a degree of originality, and it must be in a fixed medium, such as written down on paper or recorded digitally. The idea itself is not protected. That is, a copy of someone else's original idea is not infringing unless it copies that person's unique, tangible expression of the idea. Some of these limitations, especially regarding what qualifies as original, are embodied only in case law (judicial precedent), rather than in statutes.
Is there an answer to this question: What makes a copy of an unoriginal idea infringing?

Answer:
unanswerable