Nobody knows for sure how Mr Bush's two appointees, Mr Roberts and Samuel Alito, would vote.

ECONOMIST: The Supreme Court

Nobody knows for sure how the federal fiscal crisis might influence future defense spending.

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But nobody knows for sure how the currency markets would react were the pact to be diluted or even scrapped.

ECONOMIST: Europe's stability pact

Nobody knows for sure, but it is thought that millions of PCs are part of thousands of botnets across the Internet.

FORBES: Beware The Hacker's Surprising Secret Ally: Your Aunt Sally

This is the mathematical afterthought to the main body of the Standard Model, and nobody knows for sure whether it actually exists.

ECONOMIST: Particle physics makes sense, but it assumes too much

While nobody knows for sure what the Leys and hundreds of others saw, Tim Ley is sure his family will never forget that night.

CNN: What were those lights in the Phoenix sky?

While nobody knows for sure how much the Saudis have spent on getting a foothold in non-Muslim regions and especially in Western Europe and North America, the sums are clearly huge.

CENTERFORSECURITYPOLICY: Alexiev testifies on Wahhabi influence in US

The certain answer is that nobody knows for sure.

FORBES: We're Headed To $8 Natural Gas

Nobody knows for sure, but everyone is asking.

WSJ: As Games Open, Britons Excel at National Sport: Talking About Rain

Nobody quite knows for sure.

WSJ: Sacramento, Seattle? Kings fate to be decided soon