Question: The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420v DC, and a top-contact fourth rail is located centrally between the running rails at 210v DC, which combine to provide a traction voltage of 630v DC. London Underground is now upgrading its fourth rail system to 750v DC with a positive conductor rail energised to +500v DC and a negative conductor rail energised to -250v DC. However, many older sections in tunnels are still energised to 630v DC. The same system was used for Milan's earliest underground line, Milan Metro's line 1, whose more recent lines use an overhead catenary or a third rail.
Try to answer this question if possible: What type of system does London Underground use?
Answer: four-rail system
Question: In countries such as China and Vietnam, the transition to a market economy has been a major factor in a move toward the rule of law, because a rule of law is important to foreign investors and to economic development. It remains unclear whether the rule of law in countries like China and Vietnam will be limited to commercial matters or will spill into other areas as well, and if so whether that spillover will enhance prospects for related values such as democracy and human rights. The rule of law in China has been widely discussed and debated by both legal scholars and politicians in China.
Try to answer this question if possible: To whom is the rule of law important to in China's trade deals?
Answer: foreign investors
Question: As the memory of the "Charge of the Light Brigade" demonstrates, the war became an iconic symbol of logistical, medical and tactical failures and mismanagement. Public opinion in the UK was outraged at the logistical and command failures of the war; the newspapers demanded drastic reforms, and parliamentary investigations demonstrated the multiple failures of the Army. However, the reform campaign was not well organized, and the traditional aristocratic leadership of the Army pulled itself together, and blocked all serious reforms. No one was punished. The outbreak of the Indian Revolution in 1857 shifted attention to the heroic defense of British interest by the army, and further talk of reform went nowhere. The demand for professionalization was, however, achieved by Florence Nightingale, who gained worldwide attention for pioneering and publicizing modern nursing while treating the wounded.:46971
Try to answer this question if possible: Who demanded drastic reforms after the war?
Answer: the newspapers
Question: Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. Neptune was subsequently observed with a telescope on 23 September 1846 by Johann Galle within a degree of the position predicted by Urbain Le Verrier. Its largest moon, Triton, was discovered shortly thereafter, though none of the planet's remaining known 14 moons were located telescopically until the 20th century. The planet's distance from Earth gives it a very small apparent size, making it challenging to study with Earth-based telescopes. Neptune was visited by Voyager 2, when it flew by the planet on 25 August 1989. The advent of Hubble Space Telescope and large ground-based telescopes with adaptive optics has recently allowed for additional detailed observations from afar.
Try to answer this question if possible: How was Neptune found?
Answer:
mathematical prediction