This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Q: Passage: Reptiles such as adders and vipers live up to the snow line; because they cannot bear the cold temperatures they hibernate underground and soak up the warmth on rocky ledges. The high-altitude Alpine salamanders have adapted to living above the snow line by giving birth to fully developed young rather than laying eggs. Brown trout can be found in the streams up to the snow line. Molluscs such as the wood snail live up the snow line. Popularly gathered as food, the snails are now protected. Question: Why do reptiles only live up to the snow line?

A: they cannot bear the cold temperatures
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Q: Passage: In the city, the population was spread out with 21.9% at age 19 and under, 14.3% from 20 to 24, 33.2% from 25 to 44, 20.4% from 45 to 64, and 10.1% who were 65 years of age or older. The median age was 30.8 years. For every 100 females, there were 92.0 males. For every 100 females age 18 and over, there were 89.9 males. There were 252,699 households, of which 20.4% had children under the age of 18 living in them, 25.5% were married couples living together, 16.3% had a female householder with no husband present, and 54.0% were non-families. 37.1% of all households were made up of individuals and 9.0% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 3.08. Question: What percentage of the City of Boston's residents are over 65?

A: 10.1%
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Q: Passage: However, early Christian writers who speak of the shape of the particular gibbet on which Jesus died invariably describe it as having a cross-beam. For instance, the Epistle of Barnabas, which was certainly earlier than 135, and may have been of the 1st century AD, the time when the gospel accounts of the death of Jesus were written, likened it to the letter T (the Greek letter tau, which had the numeric value of 300), and to the position assumed by Moses in Exodus 17:1112. Justin Martyr (100165) explicitly says the cross of Christ was of two-beam shape: "That lamb which was commanded to be wholly roasted was a symbol of the suffering of the cross which Christ would undergo. For the lamb, which is roasted, is roasted and dressed up in the form of the cross. For one spit is transfixed right through from the lower parts up to the head, and one across the back, to which are attached the legs of the lamb." Irenaeus, who died around the end of the 2nd century, speaks of the cross as having "five extremities, two in length, two in breadth, and one in the middle, on which [last] the person rests who is fixed by the nails." Question: How many ends did the cross supposedly have?

A:
five extremities
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