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根据下面材料，回答题The idea came to Nathan Eagle, a research scientist with the Massachusetts Institute of Technology, when he was doing a teaching stint in rural Kenya. He realised that, as three-quarters of the 4.6 billion mobile-phone users worldwide live in developing countries, a useful piece of technology is now being placed in the hands of a large number of people who might be keen to use their devices to make some money. ① To help them do so, he came up with a service called txteagle which distributes small jobs via text messaging in return for small payments.Only 18% of people in the developing world have access to the Internet, but more than 50% owned a mobile-phone handset at the end of 2009 ( a number which has more than doubled since 2005 ) , according to the International Telecommunication Union. One study shows that adding ten mobile phones per 100 people in atypical developing country boosts growth in GDP per person by 0.8 percentage points.
Mr. Eagle hopes txteagle will do its bit by mobile “crowdsourcing”—breaking down jobs into small tasks and sending them to lots of individuals. These jobs often involve local knowledge and range from things like checking what street signs say in rural Sudan for a satellite-navigation service to translating words into a Kenyan dialect for companies trying to spread their marketing. ② A woman living in rural Brazil or India may have limited access to work, adds Mr. Eagle, “but she can still use her mobile phone to collect local price and product data or even complete market-research surveys.” Payments are transferred to a user's phone by a mobile money service, such as the M-PESA system run by Safaricom in Africa, or by providing additional calling credit.
Working with over 220 mobile operators, txteagle is able to reach 2 billion subscribers in 80 countries. It already has the largest contract-labour force in Kenya and new ways of using it are being found all the time．Recently a large media firm asked Mr. Eagle for help in monitoring its television commercials across Africa. The company was concerned that, although it had paid for broadcasting rights, its ads could be replaced with others by local television companies. So txteagle pays locals to watch and then text notes about which ads are shown．“I would never think of that myself,” says Mr. Eagle. Which is why he is not sure just how big all these small text jobs could become.
The one who is most likely to use txteagle is __________． A． an aggressive man aiming to make a fortune
B． a young mother who is busy with housework
C． a poor man who has just lost his job
D． a rich man who idles around the whole day
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