Problem: Please answer a question about the following article about Light-emitting diode:
In September 1961, while working at Texas Instruments in Dallas, Texas, James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically-isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc diffused pn junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias. After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs, and Lincoln Lab at MIT, the U.S. patent office issued the two inventors the patent for the GaAs infrared (IR) light-emitting diode (U.S. Patent US3293513), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first LED commercial product (the SNX-100), which employed a pure GaAs crystal to emit a 890 nm light output. In October 1963, TI announced the first commercial hemispherical LED, the SNX-110.
What was the first practical LED?
A: GaAs infrared (IR) light-emitting diode
Problem: Please answer a question about the following article about Arnold Schwarzenegger:
Schwarzenegger began weight training at the age of 15. He won the Mr. Universe title at age 20 and went on to win the Mr. Olympia contest seven times. Schwarzenegger has remained a prominent presence in bodybuilding and has written many books and articles on the sport. He is widely considered to be among the greatest bodybuilders of all times as well as its biggest icon. Schwarzenegger gained worldwide fame as a Hollywood action film icon. His breakthrough film was the sword-and-sorcery epic Conan the Barbarian in 1982, which was a box-office hit and resulted in a sequel. In 1984, he appeared in James Cameron's science-fiction thriller film The Terminator, which was a massive critical and box-office success. Schwarzenegger subsequently reprised the Terminator character in the franchise's later installments in 1991, 2003, and 2015. He appeared in a number of successful films, such as Commando (1985), The Running Man (1987), Predator (1987), Twins (1988), Total Recall (1990), Kindergarten Cop (1990) and True Lies (1994). He was nicknamed the "Austrian Oak" in his bodybuilding days, "Arnie" during his acting career, and "The Governator" (a portmanteau of "Governor" and "The Terminator", one of his best-known movie roles).
How old was Schwarzenegger when he won Mr. Universe?
A: 20
Problem: Please answer a question about the following article about Philadelphia:
In the first decades of the 19th century, Federal architecture and Greek Revival architecture were dominated by Philadelphia architects such as Benjamin Latrobe, William Strickland, John Haviland, John Notman, Thomas U. Walter, and Samuel Sloan. Frank Furness is considered Philadelphia's greatest architect of the second half of the 19th century, but his contemporaries included John McArthur, Jr., Addison Hutton, Wilson Eyre, the Wilson Brothers, and Horace Trumbauer. In 1871, construction began on the Second Empire-style Philadelphia City Hall. The Philadelphia Historical Commission was created in 1955 to preserve the cultural and architectural history of the city. The commission maintains the Philadelphia Register of Historic Places, adding historic buildings, structures, sites, objects and districts as it sees fit.
When did building begin on the Philadelphia CIty Hall?
A: 1871
Problem: Please answer a question about the following article about The Blitz:
The American observer Ingersoll reported at this time that "as to the accuracy of the bombing of military objectives, here I make no qualifications. The aim is surprisingly, astonishingly, amazingly inaccurate ... The physical damage to civilian London, to sum up, was more general and more extensive than I had imagined. The damage to military targets much less", and stated that he had seen numerous examples of untouched targets surrounded by buildings destroyed by errant bombs. For example, in two months of bombing, Battersea Power Station, perhaps the largest single target in London, had only received one minor hit ("a nick"). No bridge over the Thames had been hit, and the docks were still functioning despite great damage. An airfield was hit 56 times but the runways were never damaged and the field was never out of operation, despite German pilots' familiarity with it from prewar commercial flights. Ingersoll wrote that the difference between the failure of the German campaign against military targets versus its success in continental Europe was the RAF retaining control of the air.:7980,174
The Battersea Power Station took how many hits in two months?
A:
one minor hit ("a nick")