One very challenging problem, though, involves the process of patterning the device onto the chip.

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The more challenging problem is whether there is any way in which the objectives of the law enforcement authorities can be achieved in practice.

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All participants were then asked to complete, under time pressure, a series of challenging problem-solving tasks, for which they needed to use creativity to generate the correct solutions.

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And I know that a lot of you think that probably most attention was devoted to the speech that I delivered, the keynote speech in Boston, but in fact actually the most challenging problem was what tie to wear.

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Merck admits studying the problem is "challenging" but says the potential is big.

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Medical students will interact with Watson on challenging cases as part of a problem-based learning curriculum and in hypothetical clinical simulations.

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Part of the problem, Wettemann says is that Microsoft found it challenging communicating the strengths of what was then a very new product to its partners, not to mention would-be customers.

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