秘密工作

He’s been in the pay of our rivals for the last ten years.

十年来他一直在秘密地为我们的对手作。

Moreover, understructure work's excavation work has not completed by far, perhaps there is hiding the true secret.

而且，地下程的挖掘作还远远没有完成，也那里才隐藏着真正的秘密。