Article: As a more urban culture developed, academies provided a means of transmission for speculative and philosophical literature in early civilizations, resulting in the prevalence of literature in Ancient China, Ancient India, Persia and Ancient Greece and Rome. Many works of earlier periods, even in narrative form, had a covert moral or didactic purpose, such as the Sanskrit Panchatantra or the Metamorphoses of Ovid. Drama and satire also developed as urban culture provided a larger public audience, and later readership, for literary production. Lyric poetry (as opposed to epic poetry) was often the speciality of courts and aristocratic circles, particularly in East Asia where songs were collected by the Chinese aristocracy as poems, the most notable being the Shijing or Book of Songs. Over a long period, the poetry of popular pre-literate balladry and song interpenetrated and eventually influenced poetry in the literary medium.

Question: What are some classical societies whose literature is still studied today?
Ans: Ancient China, Ancient India, Persia and Ancient Greece and Rome

Article: To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, the others being provided to allow a feeder station to be shut down and power provided from adjacent feeder stations. Neutral Sections usually consist of an earthed section of wire which is separated from the live wires on either side by insulating material, typically ceramic beads, designed so that the pantograph will smoothly run from one section to the other. The earthed section prevents an arc being drawn from one live section to the other, as the voltage difference may be higher than the normal system voltage if the live sections are on different phases and the protective circuit breakers may not be able to safely interrupt the considerable current that would flow. To prevent the risk of an arc being drawn across from one section of wire to earth, when passing through the neutral section, the train must be coasting and the circuit breakers must be open. In many cases, this is done manually by the drivers. To help them, a warning board is provided just before both the neutral section and an advance warning some distance before. A further board is then provided after the neutral section to tell drivers to re-close the circuit breaker, although drivers must not do this until the rear pantograph has passed this board. In the UK, a system known as Automatic Power Control (APC) automatically opens and closes the circuit breaker, this being achieved by using sets of permanent magnets alongside the track communicating with a detector on the train. The only action needed by the driver is to shut off power and coast and therefore warning boards are still provided at and on the approach to neutral sections.

Question: How were the drivers warned to start coasting the train?
Ans: warning board

Article: Modern font technology provides a means to address the practical issue of needing to depict a unified Han character in terms of a collection of alternative glyph representations, in the form of Unicode variation sequences. For example, the Advanced Typographic tables of OpenType permit one of a number of alternative glyph representations to be selected when performing the character to glyph mapping process. In this case, information can be provided within plain text to designate which alternate character form to select.

Question: what tables of OpenType allow permit the selection of alternative glyph representations?
Ans: Advanced Typographic

Article: In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is based on three watt-balance measurements of KJ2RK and one inter-laboratory determination of the molar volume of silicon, but is mostly determined by a 2007 watt-balance measurement made at the U.S. National Institute of Standards and Technology (NIST). Five other measurements by three different methods were initially considered, but not included in the final refinement as they were too imprecise to affect the result.

Question: What method was was used to obtain the measurement?
Ans:
watt-balance measurement