Problem: Antenna (radio):

Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generally the reflector will remain highly reflective even if it is not solid; gaps less than 110 generally have little effect on the outcome. For this reason, reflectors often take the form of wire meshes or rows of passive elements, which makes them lighter and less subject to wind. The parabolic reflector is perhaps the best known example of a reflector-based antenna, which has an effective area far greater than the active element alone.

What effect would the use of a reflector have on a signal?
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A: increase

Problem: The oldest known fossil among the Eutheria ("true beasts") is the small shrewlike Juramaia sinensis, or "Jurassic mother from China", dated to 160 million years ago in the Late Jurassic. A later eutherian, Eomaia, dated to 125 million years ago in the Early Cretaceous, possessed some features in common with the marsupials but not with the placentals, evidence that these features were present in the last common ancestor of the two groups but were later lost in the placental lineage. In particular:
What time period is a marsupial dated to in the Early Cretaceous?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
From the end of World War II until 1971, when John Rawls published A Theory of Justice, political philosophy declined in the Anglo-American academic world, as analytic philosophers expressed skepticism about the possibility that normative judgments had cognitive content, and political science turned toward statistical methods and behavioralism. In continental Europe, on the other hand, the postwar decades saw a huge blossoming of political philosophy, with Marxism dominating the field. This was the time of Jean-Paul Sartre and Louis Althusser, and the victories of Mao Zedong in China and Fidel Castro in Cuba, as well as the events of May 1968 led to increased interest in revolutionary ideology, especially by the New Left. A number of continental European emigres to Britain and the United Statesincluding Karl Popper, Friedrich Hayek, Leo Strauss, Isaiah Berlin, Eric Voegelin and Judith Shklarencouraged continued study in political philosophy in the Anglo-American world, but in the 1950s and 1960s they and their students remained at odds with the analytic establishment.
The events of May 1968 led to an increased interest in what?
A: revolutionary ideology

Context and question: Roughly one quarter of all zinc output in the United States (2009), is consumed in the form of zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints, and as a catalyst in the manufacture of rubber. It is also used as a heat disperser for the rubber and acts to protect its polymers from ultraviolet radiation (the same UV protection is conferred to plastics containing zinc oxide). The semiconductor properties of zinc oxide make it useful in varistors and photocopying products. The zinc zinc-oxide cycle is a two step thermochemical process based on zinc and zinc oxide for hydrogen production.
Why is zinc oxide unhelpful in photocopying products?
Answer: unanswerable

Question: In July 2015, Eton accidentally sent emails to 400 prospective students, offering them conditional entrance to the school in September 2017. The email was intended for nine students, but an IT glitch caused the email to be sent to 400 additional families, who didn't necessarily have a place. In response, the school issued the following statement: "This error was discovered within minutes and each family was immediately contacted to notify them that it should be disregarded and to apologise. We take this type of incident very seriously indeed and so a thorough investigation, overseen by the headmaster Tony Little and led by the tutor for admissions, is being carried out to find out exactly what went wrong and ensure it cannot happen again. Eton College offers its sincere apologies to those boys concerned and their families. We deeply regret the confusion and upset this must have caused."
Is there an answer to this question: Who was the tutor for admissions at Eton in 2015?

Answer: unanswerable

Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was Chengu known to supply the Tibetan Empire with?
Ah, so..
unanswerable