sentence-transformers/squad huggingface dataset:
Passage: For the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames per second.

Question: What is usually dropped for the commercial naming of an HDTV product?

Question: What does 24p mean?

Question: What does 50i mean?

Question: When naming a commercial HDTV product, a frame rate can be specified without what?
Passage: There is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algorithms. When transmitted directly through the Internet, the colors are typically pre-converted to 8-bit RGB channels for additional storage savings with the assumption that it will only be viewed only on a (sRGB) computer screen. As an added benefit to the original broadcasters, the losses of the pre-conversion essentially make these files unsuitable for professional TV re-broadcasting.

Question: Is there a single standard for HDTV color support?

Question: Before being converted to RGB, colors are ususally broadcasted using what color space?

Question: Colors are typically broadcast using YUV and then converted to what?

Question: When transmitted over the internet, colors are typically to what?

Question: What assumption is made with colors being transmitted over the internet?
Passage: At a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.

Question: At least how many times more linear resolution does HDTV have over SDTV?

Question: HDTV increases the effective image resolution by not using what?

Question: What does SDTV stand for?

Question: HDTV handles what aspect ratio without using letterboxing or anamorphic stretching?
Passage: A very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed source.

Question: If more bandwith is required than is available, a very high resolution source my not be able to transmitted without loss of what?

Question: The compression used in all HDTV storage and transmission systems will do what if resolution is too high?

Question: A very high resolution source may require more of what?
Passage: The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source.

Question: A broadcasts optimum format depends on what two things?

Question: For best fidelity to the source, what three things should match the source?

Question: For best fidelity to the source, the transmitted field ratio, lines, and frame rate should match what?

Question: The type of videographic recording medium used and the image's characteristics determine what?
Passage: PAL, SECAM and NTSC frame rates technically apply only to analogue standard definition television, not to digital or high definition broadcasts. However, with the roll out of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former PAL and SECAM countries operates at a frame rate of 25/50 Hz, while HDTV in former NTSC countries operates at 30/60 Hz.

Question: PAL, SECAM, and NTSC frame rates apply to what definition televisions?

Question: PAL, SECAM, and NTSC frame rates do not apply to what broadcasts?

Question: In former PAL and SECAM countries, what frame rate does HDTV operate at?

Question: In former NTSC countries, what frame rate does HDTV operate at?
Passage: Standard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate of 25 frame/s, causing a speedup of 4.1 percent, which is generally considered acceptable. In NTSC-system countries, the TV scan rate of 30 frame/s would cause a perceptible speedup if the same were attempted, and the necessary correction is performed by a technique called 3:2 Pulldown: Over each successive pair of film frames, one is held for three video fields (1/20 of a second) and the next is held for two video fields (1/30 of a second), giving a total time for the two frames of 1/12 of a second and thus achieving the correct average film frame rate.

Question: At what rate is standard 35mm photographic film exposed and projected?

Question: To be shown on SDTV in PAL-system countries, at what rate is cinema film scanned?

Question: The technique in which with successive pair of film frames, one is held for three video fields, and the next is held for two, is called what?

Question: The 3:2 Pulldown techniques gives what total time for two frames?

Question: What is achieved by the 3:2 Pulldown technique producing a total time of 1/12 of a second for two frames?
Passage: Non-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode. 720p also imposes less strenuous storage and decoding requirements compared to both 1080i and 1080p. 1080p/24, 1080i/30, 1080i/25, and 720p/30 is most often used on Blu-ray Disc.

Question: What two formats are typically used to recorde non-cinematic HDTV video intended for broadcast?

Question: Which format is typically used for internet distribution of HD video?

Question: Most computer monitors operate in what mode?

Question: 1080i, 1080p, and 720p are often used on what kind of disc.
Passage: In the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except now the major network signals are broadcast in high definition (ABC, Fox, and Ion Television broadcast at 720p resolution; CBS, My Network TV, NBC, PBS, and The CW at 1080i). As their digital signals more efficiently use the broadcast channel, many broadcasters are adding multiple channels to their signals. Laws about antennas were updated before the change to digital terrestrial broadcasts. These new laws prohibit home owners' associations and city government from banning the installation of antennas.

Question: In the US, what kind of tuner is needed for residents to receive free, over the air programming?

Question: Laws regarding antennas were upated before what?

Question: Who do these laws prohibit from banning the installation of antennas?

Question: Laws about antennas keep home owners' associations and city government from banning what?

Question: Most television sets sold since what year have an ATSC tuner?
Passage: Additionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD.

Question: HD content can be displayed by cable-ready TVs without using what?

Question: Without using an external box, cable-ready TVs can display what?

Question: What features allow the cable-ready TVs to display HD content without an external box?

Question: What kind of built-in tuner will allow a cable-ready TV to display HD content without an external box?

Question: What kind of card will allow a cable-ready TV to display HD content without an external box?
Passage: High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV (including GoogleTV Roku boxes and AppleTV or built into "Smart Televisions"), Blu-ray video disc (BD), and internet downloads.

Question: Roku and AppleTV are examples of what?

Question: Internet downloads, Blu-ray videos, and Apple TV are examples of what?

Question: Terrestrial broadcast and direct broadcast satellite are examples of what?

Question: Digital cable and Roku are examples of what?
Passage: Sony's PlayStation 3 has extensive HD compatibility because of its built in Blu-ray disc based player, so does Microsoft's Xbox 360 with the addition of Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD content. Recently, Nintendo released a next generation high definition gaming platform, The Wii U, which includes TV remote control features in addition to IPTV streaming features like Netflix. The HD capabilities of the consoles has influenced some developers to port games from past consoles onto the PS3, Xbox 360 and Wii U, often with remastered or upscaled graphics.

Question: Why does the PlayStation 3 have extensive HD compatibility?

Question: In addition to having a Blu-ray player the Xbox 360 also features what?

Question: What high definition gaming platform did Nintendo recently release?

Question: The HD capabilities of modern gaming systems has inspired developers to do what?
Passage: HDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD recorders), or an HDTV-ready HTPC. Some cable boxes are capable of receiving or recording two or more broadcasts at a time in HDTV format, and HDTV programming, some included in the monthly cable service subscription price, some for an additional fee, can be played back with the cable company's on-demand feature.

Question: Sky HD's set-top box, TiVo's Series 3, and Dish Network's VIP 622 are examples of what?

Question: Some cable boxes are capable of doing what?

Question: What restriction does W-VHS recordings have?

Question: What does D-VHS stand for?
Passage: The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in MPEG-2 format in a .ts file or in a Blu-ray compatible format .m2ts file on the hard drive or DVD burner of a computer connected to the PVR through a USB 2.0 interface. More recent systems are able to record a broadcast high definition program in its 'as broadcast' format or transcode to a format more compatible with Blu-ray.

Question: When was the Hauppauge 1212 Personal Video Recorder introduced?

Question: How does the Personal Video Recorder store content?

Question: Recent systems can record a broadcast HD program in what format?

Question: What uncompressed storage option was introduced in 2008?
Passage: Analog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market.

Question: W-VHS recorders are capable of recording what kinds of signals?

Question: What kind of recorder is no longer produced for the consumer market?

Question: In the secondary market, analog tape recorders are considered what?
Passage: In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. As of July 2004[update], boxes are not included in the FCC mandate. This content is protected by encryption known as 5C. This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.

Question: Prior to 2004, what were US cable companies required to provide customers who rent HD set-top boxes?

Question: When were boxes with "functional" FireWire no longer included in the FCC mandate?

Question: Content is now protected by what encryption?

Question: What can 5c encryption prevent?
Passage: It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs.[citation needed] In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.

Question: In addition to being used to build things, what has wood been used for over thousands of years?

Question: What kind of strong fibers are part of the composite of wood?

Question: What's the matrix in wood made up of?

Question: What one word describes the function wood provides to a tree or plant?

Question: What does wood convey to leaves, roots, and other tissues of a woody plant in addition to water?
Passage: The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were for furniture and building construction.

Question: How many cubic meters of growing stock forest are there on the planet?

Question: What percentage of the Earth's stock forest is commercial?

Question: In addition to buildings, what is wood often used to make?

Question: About how many cubic kilometers of the vast stock forest's wood were harvested in 1991?

Question: In addition to being carbon neutral, what other adjective describes wood that makes it compelling as a renewable energy source?
Passage: A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created.

Question: What year were the earliest plants that grew wood discovered?

Question: In which Canadian province were the oldest woody plants found?

Question: If dendrochronology can't be used, what method would scientists employ to date wood?

Question: How many millions of years old were the plants that were discovered in New Brunswick?
Passage: People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time.

Question: What has been the primary purpose of wood for millennia other than fuel?

Question: What is often made of wood that provides shelter to people?

Question: For clues about the climate of a place, we can look at variation in isotopic abundances or what other thing?

Question: What could be made out of wood that could be used to fight off attackers?

Question: What category of items often constructed from wood does a chair belong to?
Passage: Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, a lateral meristem, and subsequent expansion of the new cells. Where there are clear seasons, growth can occur in a discrete annual or seasonal pattern, leading to growth rings; these can usually be most clearly seen on the end of a log, but are also visible on the other surfaces. If these seasons are annual these growth rings are referred to as annual rings. Where there is no seasonal difference growth rings are likely to be indistinct or absent.

Question: Where does wood come from?

Question: What forms in a tree to increase its diameter?

Question: What is the process of trees growing out to get bigger around called?

Question: What do many places have four of that would cause growth rings in a tree?

Question: If a place has annual seasons, what are the growth rings on the trees there called?
Passage: If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or springwood. The outer portion formed later in the season is then known as the latewood or summerwood. However, there are major differences, depending on the kind of wood (see below).

Question: If a growth ring has differences over one season, would the part nearest the tree's center be narrower or wider?

Question: What name, besides springwood, is used for the part of a growth ring formed in the beginning of the growing season?

Question: If the opposite of springwood is summerwood, what's the opposite of earlywood?

Question: Is earlywood usually lighter or darker than the part of the growth ring that forms later in the season?

Question: Is summerwood the inner or outer portion of a growth ring?
Passage: A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly circular "solid" (usually darker) piece of wood around which the grain of the rest of the wood "flows" (parts and rejoins). Within a knot, the direction of the wood (grain direction) is up to 90 degrees different from the grain direction of the regular wood.

Question: What is the sort of circular imperfection in a piece of wood called?

Question: What property of wood does a knot usually reduce in the wood around it?

Question: In what direction is wood often sawn so that a knot appears as a solid circle that the grain flows around?

Question: Are knots usually lighter or darker than the surrounding wood?

Question: The direction of grain in a knot can differ by as much as how many degrees from the regular wood?
Passage: In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud.

Question: Other than the base of a side branch, what tree feature causes a knot?

Question: What shape is the knot formed by a side branch's base?

Question: What measurement of a stem determines a knot's inner tip placement?

Question: Because a knot's shape is conical, what shape does a cross-section of it have?
Passage: During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop out after the tree has been sawn into boards.

Question: What will the lower limbs of a tree usually do during development?

Question: For what length of time can a dead lower limb stay attached to a tree?

Question: Rather than being joined to the limb that died, where do subsequent layers grow?

Question: Are the knots that dead tree limbs form attached or not attached?

Question: A detached knot will probably drop out of the wood when someone saws it into what?
Passage: In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow.

Question: What's the process in which knots are classified called?

Question: Along with firmness, soundness, and form, what property of a knot is classified?

Question: What property of knots does the amount of time a branch stayed on a tree while the stem kept growing affect?
Passage: Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compression parallel to the grain.

Question: What is wood's breaking strength susceptible to?

Question: Depending on the placement and size of a knot, what property of structural timber can be affected?

Question: What do stiffness and elastic strength depend on more than defects?

Question: What direction of compression in relation to its grain won't weaken wood with sound knots in it?
Passage: In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufacture and show as a yellow or brownish stain. A knot primer paint or solution, correctly applied during preparation, may do much to reduce this problem but it is difficult to control completely, especially when using mass-produced kiln-dried timber stocks.

Question: What positive visual component can knots sometimes add to decorative pieces?

Question: What term is used to describe what knots can do to affect the finish of things made from wood even when they've been painted?

Question: Is bleed easy or difficult to control?

Question: The stain from a knot bleeding is usually brownish or what other color?

Question: In what stage of processing does knot primer need to be applied for maximum effectiveness?
Passage: Heartwood (or duramen) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead. Some uncertainty still exists as to whether heartwood is truly dead, as it can still chemically react to decay organisms, but only once.

Question: What's another word for "duramen"?

Question: What is heartwood naturally resistant to?

Question: How does heartwood formation occur due to its being genetically programmed?

Question: What adjective describes fully formed heartwood?

Question: Despite being considered dead, what can heartwood have one chemical reaction to?