It's a total mystery,". He says brain studies are shedding light on the pieces of the puzzle and might one day solve the mystery.

VOA: standard.2010.01.15

At many times, the margin is so small, it is very difficult to solve this puzzle.

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Chris Sander, a researcher at the Massachusetts Institute of Technology, and his colleagues have tried to solve this puzzle.

ECONOMIST: Structural genomics: Strategic thinking | The

There are simply too many players attempting to solve that puzzle.

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