间谍活动

He had been engaged in emissary activity before he was discovered.

在发现以前他一直从事间谍活动。

He used his job as a screen for his spying activities.

他利用他的工作作掩间谍活动。

He was accused of spying and was declared non grata.

他指从事间谍活动而为不受欢迎。