他们还有一个共同的秘密：会议的细节，甚至他们的身份都是严格保密的。

They also share a common secret: The details of their meetings, even their identities, have been strictly confidential.

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美国研究人员声称，他们已经证明这块被前苏联情报机构秘密保存了数十年的头骨属于一位年龄不到40岁的身份不明的女性。

American researchers claim to have demonstrated that the skull fragment, secretly preserved for decades by Soviet intelligence, belonged to a woman under 40, whose identity is unknown.

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我们必须警惕地保护他们的身份秘密就像他们保护我们的安全一样，我们必须让他们满怀信心的继续工作。

We must protect their identities as vigilantly as they protect our security, and we must provide them with the confidence that they can do their jobs.

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