That information should have been passed on to U.S.databases, but it is unclear if that actually happened.

VOA: standard.2009.12.28

It's unclear which...it's only by...only in the early '80s that they've really adopted measured monetary, right?

貌似一直到80年代初期,美国政府才真正采取货币紧缩政策，对吗？

斯坦福公开课 - 经济学课程节选

There has been, over the years a lot of turf battles between the SEC and the CFTC because it's sometimes unclear whether something is a security or a futures.

历年来,证券交易委员会和期货交易委员会的领域战争层出不穷,因为有时候很难说,一个东西究竟是证券还是期货。

耶鲁公开课 - 金融市场课程节选

Although there is some evidence that artery damage caused by second-hand smoke in adults may be reversible, LaVan says it's unclear whether that's also true for adolescents.

VOA: standard.2010.03.04

Some want an independent review. And the trial's researchers, like Dr.Nelson Michael, of the Walter Reed Institute of Research in the United States, say it's unclear what difference the findings will make for areas like Africa where rates of HIV/AIDS are much higher than among the test population and where there are many strains of the virus.

VOA: standard.2009.10.20