These were not only offered the theory bedrock for the work of search and eliminate covert channels, but also given a frame for develop new search and elimination methods in covert channels.

这些工作不仅为隐通道的搜索与消除工作提供了可信的理论依据，而且为寻找新的隐通道搜索与消除方法提供了一个研究框架。

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The Assistant Chief Constable for the North Region, Norman Walmsley, said the plan included an increase in covert operations and more 'stop and search' checkpoints .

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