Problem: Vacuum:

Fluids cannot generally be pulled, so a vacuum cannot be created by suction. Suction can spread and dilute a vacuum by letting a higher pressure push fluids into it, but the vacuum has to be created first before suction can occur. The easiest way to create an artificial vacuum is to expand the volume of a container. For example, the diaphragm muscle expands the chest cavity, which causes the volume of the lungs to increase. This expansion reduces the pressure and creates a partial vacuum, which is soon filled by air pushed in by atmospheric pressure.

What moves high pressure in the atmosphere?
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A: unanswerable

Problem: In May 2005, the first high definition video conferencing systems, produced by LifeSize Communications, were displayed at the Interop trade show in Las Vegas, Nevada, able to provide video at 30 frames per second with a 1280 by 720 display resolution. Polycom introduced its first high definition video conferencing system to the market in 2006. As of the 2010s, high definition resolution for videoconferencing became a popular feature, with most major suppliers in the videoconferencing market offering it.
What did LifeSize Communications introduce in 2006?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The BBC Television department headed by Jana Bennett was absorbed into a new, much larger group; BBC Vision, in late 2006. The new group was part of larger restructuring within the BBC with the onset of new media outlets and technology.
What caused the moved of BBC Vision into the BBC Television unit?
A: unanswerable

Context and question: During the administration of U.S. President Martin Van Buren, nearly 17,000 Cherokeesalong with approximately 2,000 black slaves owned by Cherokeeswere uprooted from their homes between 1838 and 1839 and were forced by the U.S. military to march from "emigration depots" in Eastern Tennessee (such as Fort Cass) toward the more distant Indian Territory west of Arkansas. During this relocation an estimated 4,000 Cherokees died along the way west. In the Cherokee language, the event is called Nunna daul Isunyi"the Trail Where We Cried." The Cherokees were not the only American Indians forced to emigrate as a result of the Indian removal efforts of the United States, and so the phrase "Trail of Tears" is sometimes used to refer to similar events endured by other American Indian peoples, especially among the "Five Civilized Tribes". The phrase originated as a description of the earlier emigration of the Choctaw nation.
What Cherokee phrase means "the trail where we cried?"
Answer: Nunna daul Isunyi

Question: Energy sources unsuitable for mobile power plants, such as nuclear power, renewable hydroelectricity, or wind power can be used. According to widely accepted global energy reserve statistics, the reserves of liquid fuel are much less than gas and coal (at 42, 167 and 416 years respectively). Most countries with large rail networks do not have significant oil reserves and those that did, like the United States and Britain, have exhausted much of their reserves and have suffered declining oil output for decades. Therefore, there is also a strong economic incentive to substitute other fuels for oil. Rail electrification is often considered an important route towards consumption pattern reform. However, there are no reliable, peer-reviewed studies available to assist in rational public debate on this critical issue, although there are untranslated Soviet studies from the 1980s.
Is there an answer to this question: Energy sources suitable for mobile power plants include what?

Answer: unanswerable

Problem: Santa Monica, California:

In 1999, there was a double homicide in the Westside Clothing store on Lincoln Boulevard. During the incident, Culver City gang members David "Puppet" Robles and Jesse "Psycho" Garcia entered the store masked and began opening fire, killing Anthony and Michael Juarez. They then ran outside to a getaway vehicle driven by a third Culver City gang member, who is now also in custody. The clothing store was believed to be a local hang out for Santa Monica gang members. The dead included two men from Northern California who had merely been visiting the store's owner, their cousin, to see if they could open a similar store in their area. Police say the incident was in retaliation for a shooting committed by the Santa Monica 13 gang days before the Juarez brothers were gunned down.

In what year was there a double homicide?
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A:
1999