Problem: Antenna (radio):

Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generally the reflector will remain highly reflective even if it is not solid; gaps less than 110 generally have little effect on the outcome. For this reason, reflectors often take the form of wire meshes or rows of passive elements, which makes them lighter and less subject to wind. The parabolic reflector is perhaps the best known example of a reflector-based antenna, which has an effective area far greater than the active element alone.

What is the most recognized type of an antenna that has its basis in reflection?
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A: parabolic reflector

Problem: Other immune system disorders include various hypersensitivities (such as in asthma and other allergies) that respond inappropriately to otherwise harmless compounds.
What is a type of immune system disorder?
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Answer: hypersensitivities

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
At present, the full name of the government of Nanjing is "People's Government of Nanjing City" and the city is under the one-party rule of the CPC, with the CPC Nanjing Committee Secretary as the de facto governor of the city and the mayor as the executive head of the government working under the secretary.
Who is considered to be the governor of Nanjing?
A: the CPC Nanjing Committee Secretary

Context and question: Mandolin has also been used in blues music, most notably by Ry Cooder, who performed outstanding covers on his very first recordings, Yank Rachell, Johnny "Man" Young, Carl Martin, and Gerry Hundt. Howard Armstrong, who is famous for blues violin, got his start with his father's mandolin and played in string bands similar to the other Tennessee string bands he came into contact with, with band makeup including "mandolins and fiddles and guitars and banjos. And once in a while they would ease a little ukulele in there and a bass fiddle." Other blues players from the era's string bands include Willie Black (Whistler And His Jug Band), Dink Brister, Jim Hill, Charles Johnson, Coley Jones (Dallas String Band), Bobby Leecan (Need More Band), Alfred Martin, Charlie McCoy (1909-1950), Al Miller, Matthew Prater, and Herb Quinn.
What other instrument did the Tennessee string bands use?
Answer: ukulele in there and a bass fiddle

Question: The terms used to define Greekness have varied throughout history but were never limited or completely identified with membership to a Greek state. By Western standards, the term Greeks has traditionally referred to any native speakers of the Greek language, whether Mycenaean, Byzantine or modern Greek. Byzantine Greeks called themselves Romioi and considered themselves the political heirs of Rome, but at least by the 12th century a growing number of those educated, deemed themselves the heirs of ancient Greece as well, although for most of the Greek speakers, "Hellene" still meant pagan. On the eve of the Fall of Constantinople the Last Emperor urged his soldiers to remember that they were the descendants of Greeks and Romans.
Is there an answer to this question: What do the Grecian Romioi descendants of the Constantine rule believe to be false in regards to the status as beneficiaries

Answer: unanswerable

The Ptolemaic Kingdom was a powerful Hellenistic state, extending from southern Syria in the east, to Cyrene to the west, and south to the frontier with Nubia. Alexandria became the capital city and a centre of Greek culture and trade. To gain recognition by the native Egyptian populace, they named themselves as the successors to the Pharaohs. The later Ptolemies took on Egyptian traditions, had themselves portrayed on public monuments in Egyptian style and dress, and participated in Egyptian religious life.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What were the reaches of the Ptolemaic Kingdom?
Ah, so..
Syria in the east, to Cyrene to the west, and south to the frontier with Nubia