Article: Japanese seismologist Yuji Yagi at the University of Tsukuba said that the earthquake occurred in two stages: "The 155-mile Longmenshan Fault tore in two sections, the first one ripping about seven yards, followed by a second one that sheared four yards." His data also showed that the earthquake lasted about two minutes and released 30 times the energy of the Great Hanshin earthquake of 1995 in Japan, which killed over 6,000 people. He pointed out that the shallowness of the epicenter and the density of population greatly increased the severity of the earthquake. Teruyuki Kato, a seismologist at the University of Tokyo, said that the seismic waves of the quake traveled a long distance without losing their power because of the firmness of the terrain in central China. According to reports from Chengdu, the capital of Sichuan province, the earthquake tremors lasted for "about two or three minutes".

Question: How many people were killed in the Hanshin earthquake?
Ans: 6,000 people


Article: There are 366 railway stations in the London Travelcard Zones on an extensive above-ground suburban railway network. South London, particularly, has a high concentration of railways as it has fewer Underground lines. Most rail lines terminate around the centre of London, running into eighteen terminal stations, with the exception of the Thameslink trains connecting Bedford in the north and Brighton in the south via Luton and Gatwick airports. London has Britain's busiest station by number of passengers – Waterloo, with over 184 million people using the interchange station complex (which includes Waterloo East station) each year. Clapham Junction is the busiest station in Europe by the number of trains passing.

Question: Why does South London have such a high number of railways?
Ans: it has fewer Underground lines.


Article: Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded the following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City, Utah. Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red.

Question: Where were the first modern electric traffic lights erected in 1912?
Ans: Salt Lake City, Utah


Article: Other immune system disorders include various hypersensitivities (such as in asthma and other allergies) that respond inappropriately to otherwise harmless compounds.

Question: What is a type of immune system disorder?
Ans:
hypersensitivities