Input: Read this: Simultaneous videoconferencing among three or more remote points is possible by means of a Multipoint Control Unit (MCU). This is a bridge that interconnects calls from several sources (in a similar way to the audio conference call). All parties call the MCU, or the MCU can also call the parties which are going to participate, in sequence. There are MCU bridges for IP and ISDN-based videoconferencing. There are MCUs which are pure software, and others which are a combination of hardware and software. An MCU is characterised according to the number of simultaneous calls it can handle, its ability to conduct transposing of data rates and protocols, and features such as Continuous Presence, in which multiple parties can be seen on-screen at once. MCUs can be stand-alone hardware devices, or they can be embedded into dedicated videoconferencing units.
Question: What is one thing that characterizes an ISDN?

Output: unanswerable


QUES: Marvel counts among its characters such well-known superheroes as Spider-Man, Iron Man, Captain America, Wolverine, Thor, Hulk, Ant-Man, such teams as the Avengers, the Guardians of the Galaxy, the Fantastic Four, the Inhumans and the X-Men, and antagonists such as Doctor Doom, The Enchantress, Green Goblin, Ultron, Doctor Octopus, Thanos, Magneto and Loki. Most of Marvel's fictional characters operate in a single reality known as the Marvel Universe, with locations that mirror real-life cities. Characters such as Spider-Man, the Fantastic Four, the Avengers, Daredevil and Doctor Strange are based in New York City, whereas the X-Men have historically been based in Salem Center, New York and Hulk's stories often have been set in the American Southwest.

What were many real-life locations based off of?
What is the answer?
ANS: unanswerable


QUES: 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."
How many students does Eton accept each year?

ANS: unanswerable


The United States Air Force (USAF) is the aerial warfare service branch of the United States Armed Forces and one of the seven American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U.S. military to be formed, and is the largest and one of the world's most technologically advanced air forces. The USAF articulates its core functions as Nuclear Deterrence Operations, Special Operations, Air Superiority, Global Integrated ISR, Space Superiority, Command and Control, Cyberspace Superiority, Personnel Recovery, Global Precision Attack, Building Partnerships, Rapid Global Mobility and Agile Combat Support.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is the USAF?
Ah, so.. the aerial warfare service branch of the United States Armed Forces


Question: The first web browser was invented in 1990 by Sir Tim Berners-Lee. Berners-Lee is the director of the World Wide Web Consortium (W3C), which oversees the Web's continued development, and is also the founder of the World Wide Web Foundation. His browser was called WorldWideWeb and later renamed Nexus.
Try to answer this question if possible: When was the first browser created?
Answer: 1990


Context and question: Likewise, group theory helps predict the changes in physical properties that occur when a material undergoes a phase transition, for example, from a cubic to a tetrahedral crystalline form. An example is ferroelectric materials, where the change from a paraelectric to a ferroelectric state occurs at the Curie temperature and is related to a change from the high-symmetry paraelectric state to the lower symmetry ferroelectic state, accompanied by a so-called soft phonon mode, a vibrational lattice mode that goes to zero frequency at the transition.
What is the frequency of a paraelectric state before transition?
Answer:
unanswerable