Q: Extract the answer to the question from the following context. Question: Which of the following is not a factor which increased the severity of the earthquake: the density of the population, the fact it occured in two stages, or the shallowness of the epicenter? Context: 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".
A: occurred in two stages

Q: Extract the answer to the question from the following context. Question: What is the acronym for The National Historical Publications and Records Commission? Context: The National Historical Publications and Records Commission (NHPRC)the agency's grant-making armawards funds to state and local governments, public and private archives, colleges and universities, and other nonprofit organizations to preserve and publish historical records. Since 1964, the NHPRC has awarded some 4,500 grants.
A: NHPRC

Q: Extract the answer to the question from the following context. Question: What are circulators? Context: A necessary condition for the aforementioned reciprocity property is that the materials in the antenna and transmission medium are linear and reciprocal. Reciprocal (or bilateral) means that the material has the same response to an electric current or magnetic field in one direction, as it has to the field or current in the opposite direction. Most materials used in antennas meet these conditions, but some microwave antennas use high-tech components such as isolators and circulators, made of nonreciprocal materials such as ferrite. These can be used to give the antenna a different behavior on receiving than it has on transmitting, which can be useful in applications like radar.
A: high-tech components

Q: Extract the answer to the question from the following context. Question: Is it easier to notice color differences or brightness adjustments? Context: Video data may be represented as a series of still image frames. The sequence of frames contains spatial and temporal redundancy that video compression algorithms attempt to eliminate or code in a smaller size. Similarities can be encoded by only storing differences between frames, or by using perceptual features of human vision. For example, small differences in color are more difficult to perceive than are changes in brightness. Compression algorithms can average a color across these similar areas to reduce space, in a manner similar to those used in JPEG image compression. Some of these methods are inherently lossy while others may preserve all relevant information from the original, uncompressed video.
A:
changes in brightness