间谍活动

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

在发现前一直从事间谍活动。

He was accused of spying and was declared non grata.

控从事间谍活动而宣布为不受欢迎。

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

利用的工作作掩护进行间谍活动。