This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Input: Consider Input: Passage: Oxygen was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774, but Priestley is often given priority because his work was published first. The name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. Its name derives from the Greek roots ὀξύς oxys, "acid", literally "sharp", referring to the sour taste of acids and -γενής -genes, "producer", literally "begetter", because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition. Common uses of oxygen includes the production cycle of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, in oxygen therapy and life support systems in aircraft, submarines, spaceflight and diving.

Output: When did Carl Priestly discover oxygen?


Input: Consider Input: Passage: An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by metallic bonding character. An alloy may be a solid solution of metal elements (a single phase) or a mixture of metallic phases (two or more solutions). Intermetallic compounds are alloys with a defined stoichiometry and crystal structure. Zintl phases are also sometimes considered alloys depending on bond types (see also: Van Arkel-Ketelaar triangle for information on classifying bonding in binary compounds).

Output: What is always a mixture of metal and other elements?


Input: Consider Input: Passage: For guidance in practical application of Jewish law, the majority of Orthodox Jews appeal to the Shulchan Aruch ("Code of Jewish Law" composed in the 16th century by Rabbi Joseph Caro) together with its surrounding commentaries. Thus, at a general level, there is a large degree of uniformity amongst all Orthodox Jews. Concerning the details, however, there is often variance: decisions may be based on various of the standardized codes of Jewish Law that have been developed over the centuries, as well as on the various responsa. These codes and responsa may differ from each other as regards detail (and reflecting the above philosophical differences, as regards the weight assigned to these). By and large, however, the differences result from the historic dispersal of the Jews and the consequent development of differences among regions in their practices (see minhag).


Output: Who do the Orthodox Jews avoid for guidance in practical application of Jewish law?