"It is very difficult because the Americans, the support for such groups, in as much as it does exist, is very secretive,".

VOA: standard.2009.10.18

as notoriously secretive and reluctant as Aristotle, his works acquired over the centuries virtual canonical status.

这么声名狼藉地闪躲与冷淡，并未损及亚里士多德作品,几个世纪以来真正代表的权威地位。

耶鲁公开课 - 政治哲学导论课程节选

The Pakistanis and the Indians are now very secretive about how much material they produce.

VOA: standard.2010.04.06

"I think it's the biggest kept secret in the world because of its value. Meanwhile,secretive parts of the secret government are sitting on suppressed technology for free energy."

VOA: standard.2009.07.31