According to some accounts which are impossible to verify, a major barracks or security headquarters has fallen to the opposition.

据一些无法证实的报道，一个主要的兵营或安全总部已经倒向反对派一边。

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GCHQ, however, remains skeptical, stating that without the exact codebook, or full details of the encryption, it's impossible to verify any alleged solution.

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But like most of the information coming out of Tehran, it is impossible to verify her name -- Neda -- or the circumstances of her apparent death.

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It remained impossible to verify activists' accounts of the fighting in Homs or to confirm casualty tolls.

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