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.

Example Input: Passage: Between 2000 and 2004 an average of 478 crimes were reported each day in Mexico City; however, the actual crime rate is thought to be much higher "since most people are reluctant to report crime". Under policies enacted by Mayor Marcelo Ebrard between 2009 and 2011, Mexico City underwent a major security upgrade with violent and petty crime rates both falling significantly despite the rise in violent crime in other parts of the country. Some of the policies enacted included the installation of 11,000 security cameras around the city and a very large expansion of the police force. Mexico City has one of the world's highest police officer-to-resident ratios, with one uniformed officer per 100 citizens. Question: What Mexican mayor tried to crack down on crime immensely?
Example Output: Marcelo Ebrard

Example Input: Passage: Children working at a young age has been a consistent theme throughout Africa. Many children began first working in the home to help their parents run the family farm. Children in Africa today are often forced into exploitative labour due to family debt and other financial factors, leading to ongoing poverty. Other types of domestic child labour include working in commercial plantations, begging, and other sales such as boot shining. In total, there is an estimated five million children who are currently working in the field of agriculture which steadily increases during the time of harvest. Along with 30 percent of children who are picking coffee, there are an estimated 25,000 school age children who work year round. Question: How many children in Africa pick coffee?
Example Output: 30 percent

Example Input: Passage: Glaciers pick up rocks and sediment with them as they flow. This causes erosion and the formation of valleys over time. The Inn valley is an example of a valley carved by glaciers during the ice ages with a typical terraced structure caused by erosion. Eroded rocks from the most recent ice age lie at the bottom of the valley while the top of the valley consists of erosion from earlier ice ages. Glacial valleys have characteristically steep walls (reliefs); valleys with lower reliefs and talus slopes are remnants of glacial troughs or previously infilled valleys. Moraines, piles of rock picked up during the movement of the glacier, accumulate at edges, center and the terminus of glaciers. Question: Where have moraines accumulated?
Example Output:
at edges, center and the terminus of glaciers.