It strikes me that trying to define where the front lines are might become a very difficult problem in wartime.

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But Mr Clegg said the government had come up with a "fair and progressive solution to a very difficult problem".

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They have been asking the U.S. forces at checkpoints not to search the Iraqi women, but that is a very difficult problem that coalition security forces will have to work out.

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My wife had a very serious and difficult problem, and her GP advised that the only hospitals she should consider were Mass General and Beth Israel.

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That is a very, very difficult problem to address.

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And they have a tremendous amount of capacity of resources to deal with this very difficult problem, but it is a crisis significant enough that a lot of countries, including the United States, led by the United States, have come in to offer further aid and assistance and expertise to help them deal with it.

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The problem: very difficult to generate a sustainable revenue model.

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From my perspective, this is a simple problem that has very complicated politics and emotion that make it difficult to make progress.

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"Ninety minutes of Premiership football would be very difficult at the moment but to come on as a substitute would be no problem, " added Smith.

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The problem with that method is that it is very difficult for referees to deliver a fixed match.

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