Problem: Light-emitting diode:

In 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein".. had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier, and played back by a loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." This setup presaged the use of LEDs for optical communication applications.

The current in radio communication had to go through what type of component?
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A: unanswerable

Problem: Most of the Korean Presbyterian denominations share the same name in Korean, (literally means the Presbyterian Church of Korea or PCK), tracing its roots to the United Presbyterian Assembly before its long history of disputes and schisms. The Presbyterian schism began with the controversy in relation to the Japanese shrine worship enforced during the Japanese colonial period and the establishment of a minor division (Koryu-pa, , later The Koshin Presbyterian Church in Korea, Koshin ) in 1952. And in 1953 the second schism happened when the theological orientation of the Chosun Seminary (later Hanshin University) founded in 1947 could not be tolerated in the PCK and another minor group (The Presbyterian Church in the Republic of Korea, Kijang, ) was separated. The last major schism had to do with the issue of whether the PCK should join the WCC. The controversy divided the PCK into two denominations, The Presbyterian Church of Korea (Tonghap, ) and The General Assembly of Presbyterian Church in Korea (Hapdong, ) in 1959. All major seminaries associated with each denomination claim heritage from the Pyung Yang Theological Seminary, therefore, not only Presbyterian University and Theological Seminary and Chongsin University which are related to PCK but also Hanshin University of PROK all celebrated the 100th class in 2007, 100 years from the first graduates of Pyung Yang Theological Seminary.
In what year did the Korean church celebrate the 100th class?
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Answer: 2007

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
122nd Street is mentioned in the movie Taxi Driver by main character Travis Bickle as the location where a fellow cab driver is assaulted with a knife. The street and the surrounding neighborhood of Harlem is then referred to as "Mau Mau Land" by another character named Wizard, slang indicating it is a majority black area.
Who is the main character in Taxi Driver?
A: Travis Bickle

Context and question: First recognized in 1900 by Max Planck, it was originally the proportionality constant between the minimal increment of energy, E, of a hypothetical electrically charged oscillator in a cavity that contained black body radiation, and the frequency, f, of its associated electromagnetic wave. In 1905 the value E, the minimal energy increment of a hypothetical oscillator, was theoretically associated by Einstein with a "quantum" or minimal element of the energy of the electromagnetic wave itself. The light quantum behaved in some respects as an electrically neutral particle, as opposed to an electromagnetic wave. It was eventually called the photon.
Instead of an electromagnetic wave, what did the light quantum behave as in some regards?
Answer: an electrically neutral particle

Question: A state's consent may be invalidated if there was an erroneous understanding of a fact or situation at the time of conclusion, which formed the "essential basis" of the state's consent. Consent will not be invalidated if the misunderstanding was due to the state's own conduct, or if the truth should have been evident.
Is there an answer to this question: What, if it formed the "essential basis" of a state's consent to a treaty, may invalidate that consent?

Answer: an erroneous understanding of a fact or situation

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Having removed the monarchical government, Gaddafi proclaimed the foundation of the Libyan Arab Republic. Addressing the populace by radio, he proclaimed an end to the "reactionary and corrupt" regime, "the stench of which has sickened and horrified us all." Due to the coup's bloodless nature, it was initially labelled the "White Revolution", although was later renamed the "One September Revolution" after the date on which it occurred. Gaddafi insisted that the Free Officers' coup represented a revolution, marking the start of widespread change in the socio-economic and political nature of Libya. He proclaimed that the revolution meant "freedom, socialism, and unity", and over the coming years implemented measures to achieve this.
What was the name of the government Gaddafi set up after overthrowing the monarchy?
A:
Libyan Arab Republic