Input: Read this: Forest gardening was also being used as a food production system in various parts of the world over this period. Forest gardens originated in prehistoric times along jungle-clad river banks and in the wet foothills of monsoon regions.[citation needed] In the gradual process of families improving their immediate environment, useful tree and vine species were identified, protected and improved, whilst undesirable species were eliminated. Eventually superior foreign species were selected and incorporated into the gardens.
Question: When families were trying to ruin their immediate environment, undesirable species were what?

Output: unanswerable


QUES: The eligible age-range for contestants is currently fifteen to twenty-eight years old. The initial age limit was sixteen to twenty-four in the first three seasons, but the upper limit was raised to twenty-eight in season four, and the lower limit was reduced to fifteen in season ten. The contestants must be legal U.S. residents, cannot have advanced to particular stages of the competition in previous seasons (varies depending on the season, currently by the semi-final stage until season thirteen), and must not hold any current recording or talent representation contract by the semi-final stage (in previous years by the audition stage).

Currently, contestants can not have a recording track by what stage of the competition? 
What is the answer?
ANS: semi-final stage


QUES: The European powers recognized the islands as part of the Spanish East Indies in 1874. However, Spain sold the islands to the German Empire in 1884, and they became part of German New Guinea in 1885. In World War I the Empire of Japan occupied the Marshall Islands, which in 1919 the League of Nations combined with other former German territories to form the South Pacific Mandate. In World War II, the United States conquered the islands in the Gilbert and Marshall Islands campaign. Along with other Pacific Islands, the Marshall Islands were then consolidated into the Trust Territory of the Pacific Islands governed by the US. Self-government was achieved in 1979, and full sovereignty in 1986, under a Compact of Free Association with the United States. Marshall Islands has been a United Nations member state since 1991.
Who bought the Marshall Islands from the Spanish in 1884?

ANS: the German Empire


When optimally designed within a given core saturation constraint and for a given active current (i.e., torque current), voltage, pole-pair number, excitation frequency (i.e., synchronous speed), and air-gap flux density, all categories of electric motors or generators will exhibit virtually the same maximum continuous shaft torque (i.e., operating torque) within a given air-gap area with winding slots and back-iron depth, which determines the physical size of electromagnetic core. Some applications require bursts of torque beyond the maximum operating torque, such as short bursts of torque to accelerate an electric vehicle from standstill. Always limited by magnetic core saturation or safe operating temperature rise and voltage, the capacity for torque bursts beyond the maximum operating torque differs significantly between categories of electric motors or generators.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What aren't factors that determine shaft torque?
Ah, so.. unanswerable


Question: On 18 June 1948, the National Security Council issued Directive 10/2 calling for covert action against the USSR, and granting the authority to carry out covert operations against "hostile foreign states or groups" that could, if needed, be denied by the U.S. government. To this end, the Office of Policy Coordination was created inside the new CIA. The OPC was quite unique; Frank Wisner, the head of the OPC, answered not to the CIA Director, but to the secretaries of defense, state, and the NSC, and the OPC's actions were a secret even from the head of the CIA. Most CIA stations had two station chiefs, one working for the OSO, and one working for the OPC.
Try to answer this question if possible: Directive 10/2 called for actions against who?
Answer: the USSR


Question: The bacillus causing tuberculosis, M. tuberculosis, was identified and described on 24 March 1882 by Robert Koch. He received the Nobel Prize in physiology or medicine in 1905 for this discovery. Koch did not believe the bovine (cattle) and human tuberculosis diseases were similar, which delayed the recognition of infected milk as a source of infection. Later, the risk of transmission from this source was dramatically reduced by the invention of the pasteurization process. Koch announced a glycerine extract of the tubercle bacilli as a "remedy" for tuberculosis in 1890, calling it "tuberculin". While it was not effective, it was later successfully adapted as a screening test for the presence of pre-symptomatic tuberculosis. The World Tuberculosis Day was established on 24 March for this reason.
Try to answer this question if possible: What did Koch call the ineffective treatment for TB he came up with in 1890?
Answer:
tuberculin