Input: Antenna (radio)
A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current in the opposite direction. Most materials used in antennas meet these conditions, but some microwave antennas use high-tech components such as isolators and circulators, made of nonreciprocal materials such as ferrite. These can be used to give the antenna a different behavior on receiving than it has on transmitting, which can be useful in applications like radar.

What must be true of the antenna and transmission medium for the repiprocity rule to apply ?
Output: linear and reciprocal


Input: Article: Apple has generally dominated the premium PC market, having a 91 percent market share for PCs priced at more than $1,000 in 2009, according to NPD. The Macintosh took 45 percent of operating profits in the PC industry during Q4 2012, compared to 13 percent for Dell, seven percent for Hewlett Packard, six percent for Lenovo and Asus, and one percent for Acer. While sales of the Macintosh have largely held steady, in comparison to Apple's sales of the iPhone and iPad which increased significantly during the 2010s, Macintosh computers still enjoy high margins on a per unit basis, with the majority being their MacBooks that are focused on the ultraportable niche that is the most profitable and only growing segment of PCs. It also helped that the Macintosh lineup is simple, updated on a yearly schedule, and consistent across both Apple retail stores, and authorized resellers where they have a special "store within a store" section to distinguish them from Windows PCs. In contrast, Windows PC manufacturers generally have a wide range of offerings, selling only a portion through retail with a full selection on the web, and often with limited-time or region-specific models. The Macintosh ranked third on the "list of intended brands for desktop purchases" for the 2011 holiday season, then moved up to second in 2012 by displacing Hewlett Packard, and in 2013 took the top spot ahead of Dell.

Now answer this question: What was Macintosh ranked on the "list of intended brands for desktop purchases" for the 2011 holiday season?

Output: third


Article: Inflammatory diarrhea occurs when there is damage to the mucosal lining or brush border, which leads to a passive loss of protein-rich fluids and a decreased ability to absorb these lost fluids. Features of all three of the other types of diarrhea[clarification needed] can be found in this type of diarrhea. It can be caused by bacterial infections, viral infections, parasitic infections, or autoimmune problems such as inflammatory bowel diseases. It can also be caused by tuberculosis, colon cancer, and enteritis.[citation needed]

Question: What happens with inflammatory diarrhea?
Ans: a passive loss of protein-rich fluids and a decreased ability to absorb these lost fluids


Here is a question about this article: In 2003, a congestion charge was introduced to reduce traffic volumes in the city centre. With a few exceptions, motorists are required to pay £10 per day to drive within a defined zone encompassing much of central London. Motorists who are residents of the defined zone can buy a greatly reduced season pass. London government initially expected the Congestion Charge Zone to increase daily peak period Underground and bus users by 20,000 people, reduce road traffic by 10 to 15 per cent, increase traffic speeds by 10 to 15 per cent, and reduce queues by 20 to 30 per cent. Over the course of several years, the average number of cars entering the centre of London on a weekday was reduced from 195,000 to 125,000 cars – a 35-per-cent reduction of vehicles driven per day.
What is the answer to this question: What services were anticipated to be greatly increased as a result of the congestion charge zone?
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So... Underground and bus


The problem: Answer a question about this article:
Admiral Grace Hopper, an American computer scientist and developer of the first compiler, is credited for having first used the term "bugs" in computing after a dead moth was found shorting a relay in the Harvard Mark II computer in September 1947.
Who was the developer of the first compier?
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The answer: Admiral Grace Hopper


The problem: Answer a question about this article:
The Shang dynasty oracle bone script and the Zhou dynasty scripts found on Chinese bronze inscriptions are no longer used; the oldest script that is still in use today is the Seal Script (篆書(书), zhuànshū). It evolved organically out of the Spring and Autumn period Zhou script, and was adopted in a standardized form under the first Emperor of China, Qin Shi Huang. The seal script, as the name suggests, is now used only in artistic seals. Few people are still able to read it effortlessly today, although the art of carving a traditional seal in the script remains alive; some calligraphers also work in this style.
What script is the oldest and still in use today?
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The answer:
Seal