Some of the commercial activities were a cover for espionage.

有些商业活动是为间谍活动提供掩护。

《牛津词典》

If a case can be made that Felix Bloch engaged in espionage activities for the Soviet Union, the United States government must prosecute him.

CENTERFORSECURITYPOLICY: The Felix Bloch Affair: Assessing The Damage To US Security

"Without press credentials and under the name of being a reporter, she was carrying out espionage activities, " Hassan Haddad, a deputy public prosecutor, recently told the Iranian Student's News Agency.

CNN: Journalist's release prompts praise from Washington

Published reports indicate that nuclear attacks against the United States are still being exercised (see the Washington Times, 14 September 1993) and Russian espionage activities in Germany are being conducted as aggressively as ever (see the New York Times, 14 September 1993).

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