input question: Question: "Why was there originally a need for vacuum powered instuments on an aircraft?" Context: "Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indicator (HI)) are typically vacuum-powered, as protection against loss of all (electrically powered) instruments, since early aircraft often did not have electrical systems, and since there are two readily available sources of vacuum on a moving aircraftthe engine and an external venturi. Vacuum induction melting uses electromagnetic induction within a vacuum." Answer:???
output answer: since early aircraft often did not have electrical systems

Question: "Which doings of Alexander III's did not withstand the test of time?" Context: "Following the assassination of Phillip II, his son Alexander III ("The Great") assumed the leadership of the League of Corinth and launched an invasion of the Persian Empire with the combined forces of all Greek states in 334 BC. Undefeated in battle, Alexander had conquered the Persian Empire in its entirety by 330 BC. By the time of his death in 323 BC, he had created one of the largest empires in history, stretching from Greece to India. His empire split into several kingdoms upon his death, the most famous of which were the Seleucid Empire, Ptolemaic Egypt, the Greco-Bactrian Kingdom and the Indo-Greek Kingdom. Many Greeks migrated to Alexandria, Antioch, Seleucia and the many other new Hellenistic cities in Asia and Africa. Although the political unity of Alexander's empire could not be maintained, it resulted in the Hellenistic civilization and spread the Greek language and Greek culture in the territories conquered by Alexander. Greek science, technology and mathematics are generally considered to have reached their peak during the Hellenistic period." Answer:
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Answer: the political unity of Alexander's empire

Q: Question: "Which of the following is not a characteristic of a championship: lineage, caliber of performers, or perception?" Context: "Behind the scenes, the bookers in a company will place the title on the most accomplished performer, or those the bookers believe will generate fan interest in terms of event attendance and television viewership. Lower ranked titles may also be used on the performers who show potential, thus allowing them greater exposure to the audience. However other circumstances may also determine the use of a championship. A combination of a championship's lineage, the caliber of performers as champion, and the frequency and manner of title changes, dictates the audience's perception of the title's quality, significance and reputation." Answer:
A: perception

Question: Question: "what is the fucntion of the epidermis" Context: "The epidermis is typically 10 to 30 cells thick; its main function is to provide a waterproof layer. Its outermost cells are constantly lost; its bottommost cells are constantly dividing and pushing upward. The middle layer, the dermis, is 15 to 40 times thicker than the epidermis. The dermis is made up of many components, such as bony structures and blood vessels. The hypodermis is made up of adipose tissue. Its job is to store lipids, and to provide cushioning and insulation. The thickness of this layer varies widely from species to species." Answer:
Answer: provide a waterproof layer

[Q]: Question: "What is the duration of a poly-sided wrestling match?" Context: "Sometimes, poly-sided matches that pit every one for themselves will incorporate tagging rules. Outside of kayfabe, this is done to give wrestlers a break from the action (as these matches tend to go on for long periods of time), and to make the action in the ring easier to choreograph. One of the most mainstream examples of this is the four-corner match, the most common type of match in the WWE before it was replaced with its equivalent fatal four-way; four wrestlers, each for themselves, fight in a match, but only two wrestlers can be in the match at any given time. The other two are positioned in the corner, and tags can be made between any two wrestlers." Answer:
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[A]: long periods of time

Problem: Given the question: Question: "When had Kanye West called Bush a racist?" Context: "Bush stated in an interview that the comment was "one of the most disgusting moments" of his presidency. In November 2010, in a taped interview with Matt Lauer for the Today show, West expressed regret for his criticism of Bush. "I would tell George Bush in my moment of frustration, I didn't have the grounds to call him a racist", he told Lauer. "I believe that in a situation of high emotion like that we as human beings don't always choose the right words." The following day, Bush reacted to the apology in a live interview with Lauer saying he appreciated the rapper's remorse. "I'm not a hater", Bush said. "I don't hate Kanye West. I was talking about an environment in which people were willing to say things that hurt. Nobody wants to be called a racist if in your heart you believe in equality of races." Reactions were mixed, but some felt that West had no need to apologize. "It was not the particulars of your words that mattered, it was the essence of a feeling of the insensitivity towards our communities that many of us have felt for far too long", argued Def Jam co-founder Russell Simmons. Bush himself was receptive to the apology, saying, "I appreciate that. It wasn't just Kanye West who was talking like that during Katrina, I cited him as an example, I cited others as an example as well. You know, I appreciate that."" Answer:
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The answer is:
during Katrina