input question: Extract the answer to the question from the following context. Question: Darwin studied what concept related to rock pigeons? Context: Chapter I covers animal husbandry and plant breeding, going back to ancient Egypt. Darwin discusses contemporary opinions on the origins of different breeds under cultivation to argue that many have been produced from common ancestors by selective breeding. As an illustration of artificial selection, he describes fancy pigeon breeding, noting that "[t]he diversity of the breeds is something astonishing", yet all were descended from one species of rock pigeon. Darwin saw two distinct kinds of variation: (1) rare abrupt changes he called "sports" or "monstrosities" (example: ancon sheep with short legs), and (2) ubiquitous small differences (example: slightly shorter or longer bill of pigeons). Both types of hereditary changes can be used by breeders. However, for Darwin the small changes were most important in evolution.???
output answer: artificial selection

input question: Extract the answer to the question from the following context. Question: What problem negatively affected the display of iPod Nanos when the first generation was released? Context: iPods have been criticized for alleged short life-span and fragile hard drives. A 2005 survey conducted on the MacInTouch website found that the iPod line had an average failure rate of 13.7% (although they note that comments from respondents indicate that "the true iPod failure rate may be lower than it appears"). It concluded that some models were more durable than others. In particular, failure rates for iPods employing hard drives was usually above 20% while those with flash memory had a failure rate below 10%. In late 2005, many users complained that the surface of the first generation iPod Nano can become scratched easily, rendering the screen unusable. A class action lawsuit was also filed. Apple initially considered the issue a minor defect, but later began shipping these iPods with protective sleeves.[citation needed]???
output answer: become scratched easily

input question: Extract the answer to the question from the following context. Question: What was done to change how a computing machine worked? Context: Early computing machines had fixed programs. Changing its function required the re-wiring and re-structuring of the machine. With the proposal of the stored-program computer this changed. A stored-program computer includes by design an instruction set and can store in memory a set of instructions (a program) that details the computation. The theoretical basis for the stored-program computer was laid by Alan Turing in his 1936 paper. In 1945 Turing joined the National Physical Laboratory and began work on developing an electronic stored-program digital computer. His 1945 report 'Proposed Electronic Calculator' was the first specification for such a device. John von Neumann at the University of Pennsylvania, also circulated his First Draft of a Report on the EDVAC in 1945.???
output answer: re-wiring and re-structuring

input question: Extract the answer to the question from the following context. Question: How much is the average one room Bern apartment in euros? Context: As of 2003[update] the average price to rent an average apartment in Bern was 1108.92 Swiss francs (CHF) per month (US$890, 500, 710 approx. exchange rate from 2003). The average rate for a one-room apartment was 619.82 CHF (US$500, 280, 400), a two-room apartment was about 879.36 CHF (US$700, 400, 560), a three-room apartment was about 1040.54 CHF (US$830, 470, 670) and a six or more room apartment cost an average of 2094.80 CHF (US$1680, 940, 1340). The average apartment price in Bern was 99.4% of the national average of 1116 CHF. The vacancy rate for the municipality, in 2010[update], was 0.45%.???
output answer:
400