Input: Read this: The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in cathodic protection (CP). For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from zinc to the pipe. Zinc acts as the anode (negative terminus) by slowly corroding away as it passes electric current to the steel pipeline.[note 2] Zinc is also used to cathodically protect metals that are exposed to sea water from corrosion. A zinc disc attached to a ship's iron rudder will slowly corrode, whereas the rudder stays unattacked. Other similar uses include a plug of zinc attached to a propeller or the metal protective guard for the keel of the ship.
Question: Why is zinc not able to ever corrode?

Output: unanswerable


Input: Read this: The Ottoman Islamic legal system was set up differently from traditional European courts. Presiding over Islamic courts would be a Qadi, or judge. Since the closing of the ijtihad, or Gate of Interpretation, Qadis throughout the Ottoman Empire focused less on legal precedent, and more with local customs and traditions in the areas that they administered. However, the Ottoman court system lacked an appellate structure, leading to jurisdictional case strategies where plaintiffs could take their disputes from one court system to another until they achieved a ruling that was in their favor.
Question: What is another word for Qadi?

Output: judge


Input: Read this: After many other more or less successful attempts with relatively weak rotating and reciprocating apparatus the Prussian Moritz von Jacobi created the first real rotating electric motor in May 1834 that actually developed a remarkable mechanical output power. His motor set a world record which was improved only four years later in September 1838 by Jacobi himself. His second motor was powerful enough to drive a boat with 14 people across a wide river. It was not until 1839/40 that other developers worldwide managed to build motors of similar and later also of higher performance.
Question:  How long did it take for Jacobi's second world record to be broken?

Output: unanswerable


Input: Read this: In an effort to conserve water, Tucson is recharging groundwater supplies by running part of its share of CAP water into various open portions of local rivers to seep into their aquifer. Additional study is scheduled to determine the amount of water that is lost through evaporation from the open areas, especially during the summer. The City of Tucson already provides reclaimed water to its inhabitants, but it is only used for "applications such as irrigation, dust control, and industrial uses." These resources have been in place for more than 27 years, and deliver to over 900 locations.
Question: How long has Tucson's water conservation efforts been underway?

Output:
more than 27 years