"We do not know yet if the mail presented a threat, " said Levin, the chairman of the Senate Armed Services Committee.

CNN: Ricin scare rattles Washington

On top of this, while the Fed remains easy, we simply do not know yet whether or not QE3 aka Operation Twist gets extended past its June 30th sunset.

FORBES: In Which Downtown Josh Brown Ruins Your Summer

But every study on the use of fish oil for improving mental health comes with the warning not to overinterpret the findings, because the truth is, we simply do not yet know enough to make sweeping assertions in favor of megadosing on fish oil.

FORBES: The Fish Oil Debate: Great Brain Medicine, or Just an Expensive Placebo?

We do not yet know what will happen to these men and women or to their children.

CNN: Text of Bush's Notre Dame speech

But right now, there are men and women at work in laboratories, men and women whose names we do not yet know.

CNN: Commentary: Heroes in lab coats

Of course, we do not yet know what motivated the bombers.

CNN: Vengeance shouldn't guide prosecution

"What we do not yet know is whether this reproductive success is linked with potential longevity, " he told the 21st annual conference of the European Society of Human Reproduction and Endocrinology.

BBC: NEWS | Health | Genes help women over 45 conceive

We do not yet know exactly what Angela Merkel means by "fiscal union" but we had a dress rehearsal when a Bundestag committee learned details of a rise in Irish VAT weeks before the Irish Dail.

BBC: Northern Ireland

They show that in all three sectors there was an increase in the third quarter of last year but we do not yet know how well - or badly - Northern Ireland performed for the final quarter.

BBC: NI economy remains 'fragile'

We do not claim to know all the ways of Providence, yet we can trust in them, placing our confidence in the loving god behind all of life and all of history.

CNN: Transcript of State of the Union

If we are honest with ourselves we'll admit that there are too many who do not yet know in their lives or feel in their hearts the urgency of this struggle.

WHITEHOUSE: President Obama Speaks for Gay Civil Rights

Advertisement in Media, Banking and Oil industries are making huge revenues yet it barely impresses us, we do not even know the names behind those companies.

FORBES: Why Mark Zuckerberg Is The Heir To Steve Jobs' Legacy

We all know that short term loan are made to clients that you do not fully trust yet you are willing to give an opportunity.

FORBES: Bloomberg Backs Goldman Sachs Over Ex-Employee Op-Ed