The exact number is a state secret.

准确的数字属于国家秘密。

youdao

The real performance of the aircraft, however, remains a state secret.

J-10的真实性能，仍然是一个国家秘密。

youdao

Without the approval of the original organ or entity which determined a state secret or its superior, no one shall copy or extract them.

未经原定密机关、单位或者其上级机关批准，不得复制和摘抄；

youdao

The Supreme Court accepted the idea of a state secret privilege more than 50 years ago.

NPR: Invoking the State Secrets Privilege

Resisting calls for more transparency, President Obiang has for long held that oil revenues are a state secret.

BBC: Equatorial Guinea profile

The oil revenues of Equatorial Guinea, where three-quarters of the population live below the poverty line, are a state secret.

ECONOMIST: Africa, oil and the West: Show us the money | The