input: Please answer the following: Extract the answer to the question from the following context. Question: Why are proton pumps necessary for nutrient uptake? Context: Plants uptake essential elements from the soil through their roots and from the air (consisting of mainly nitrogen and oxygen) through their leaves. Green plants obtain their carbohydrate supply from the carbon dioxide in the air by the process of photosynthesis. Carbon and oxygen are absorbed from the air, while other nutrients are absorbed from the soil. Nutrient uptake in the soil is achieved by cation exchange, wherein root hairs pump hydrogen ions (H+) into the soil through proton pumps. These hydrogen ions displace cations attached to negatively charged soil particles so that the cations are available for uptake by the root. In the leaves, stomata open to take in carbon dioxide and expel oxygen. The carbon dioxide molecules are used as the carbon source in photosynthesis.
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output: root hairs pump hydrogen ions (H+) into the soil through proton pumps

Please answer this: Extract the answer to the question from the following context. Question: Guns with long spirally grooved barrels are called? Context: On July 16, 1989, the Popular Front of Azerbaijan held its first congress and elected Abulfaz Elchibey, who would become President, as its Chairman. On August 19, 600,000 protesters jammed Baku’s Lenin Square (now Azadliq Square) to demand the release of political prisoners. In the second half of 1989, weapons were handed out in Nagorno-Karabakh. When Karabakhis got hold of small arms to replace hunting rifles and crossbows, casualties began to mount; bridges were blown up, roads were blockaded, and hostages were taken.
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Answer: rifles

Problem: Extract the answer to the question from the following context. Question: What happens when the sun is below the horizon? Context: In nature, the red color of blood comes from hemoglobin, the iron-containing protein found in the red blood cells of all vertebrates. The red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. It also causes the red color of the planet Mars. The red sky at sunset and sunrise is caused by an optical effect known as Rayleigh scattering, which, when the sun is low or below the horizon, increases the red-wavelength light that reaches the eye. The color of autumn leaves is caused by pigments called anthocyanins, which are produced towards the end of summer, when the green chlorophyll is no longer produced. One to two percent of the human population has red hair; the color is produced by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin.

A: Rayleigh scattering

Problem: Given the question: Extract the answer to the question from the following context. Question: Which happened first, individual republics took over for the central government, or Russian deputies were recalled? Context: On the night of December 25, 1991, at 7:32 p.m. Moscow time, after Gorbachev left the Kremlin, the Soviet flag was lowered for the last time, and the Russian tricolor was raised in its place, symbolically marking the end of the Soviet Union. The next day, December 26, 1991, the Council of Republics, the upper chamber of the Union's Supreme Soviet, issued a formal Declaration recognizing that the Soviet Union had ceased to exist as a state and subject of international law, and voted both itself and the Soviet Union out of existence (the other chamber of the Supreme Soviet, the Council of the Union, had been unable to work since December 12, 1991, when the recall of the Russian deputies left it without a quorum). The following day Yeltsin moved into Gorbachev's former office, though the Russian authorities had taken over the suite two days earlier. By December 31, 1991, the few remaining Soviet institutions that had not been taken over by Russia ceased operation, and individual republics assumed the central government's role.
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The answer is:
the recall of the Russian deputies

input question: Extract the answer to the question from the following context. Question: What makes computers available to all income ranges? Context: Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed only in large and powerful machines such as supercomputers, mainframe computers and servers. Multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result.???
output answer: increasingly used in lower-end markets as a result

input question: Extract the answer to the question from the following context. Question: What is unique about owls? Context: Many birds show plumage patterns in ultraviolet that are invisible to the human eye; some birds whose sexes appear similar to the naked eye are distinguished by the presence of ultraviolet reflective patches on their feathers. Male blue tits have an ultraviolet reflective crown patch which is displayed in courtship by posturing and raising of their nape feathers. Ultraviolet light is also used in foraging—kestrels have been shown to search for prey by detecting the UV reflective urine trail marks left on the ground by rodents. The eyelids of a bird are not used in blinking. Instead the eye is lubricated by the nictitating membrane, a third eyelid that moves horizontally. The nictitating membrane also covers the eye and acts as a contact lens in many aquatic birds. The bird retina has a fan shaped blood supply system called the pecten. Most birds cannot move their eyes, although there are exceptions, such as the great cormorant. Birds with eyes on the sides of their heads have a wide visual field, while birds with eyes on the front of their heads, such as owls, have binocular vision and can estimate the depth of field. The avian ear lacks external pinnae but is covered by feathers, although in some birds, such as the Asio, Bubo and Otus owls, these feathers form tufts which resemble ears. The inner ear has a cochlea, but it is not spiral as in mammals.???
output answer:
have binocular vision and can estimate the depth of field