Let us say I want to sell my car but I do not know exactly how much it is worth.

VOA: special.2009.04.12

Doctors do not know exactly how the brain stimulation works to help patients with Parkinson's.

VOA: special.2009.02.03

"You do not know how bad that is going to be. There have been children who have died from the swine flu,".

VOA: standard.2009.12.18

They know how to win over there,". The differences in opinion among veterans over what to do in Afghanistan reflect a broader uncertainty among the American public, says pollster Peter Brown.

VOA: standard.2009.11.16

Dr.Vallenas says many mothers are discouraged from breast-feeding because they do not know how to get their baby to latch on properly to the breast's nipple, or because they suffer pain and discomfort.

VOA: standard.2009.08.01

"that are against this move-are asking is this, 'How do we know that the Americans and the West are basically going to let the Russians live up to their promise of giving the uranium back?

VOA: standard.2009.10.28

"I would say that it is my crisis training in the airline industry that helped me know at that moment when you feel emotionally paralyzed what to do and how to start communicating that sad news."

VOA: standard.2010.02.25

How do we know that they are not going to keep it all?" The United States and allies France and Russia have supported the IAEA draft deal with Iran as a means to alleviate concerns that Tehran is using its nuclear program to develop atomic weapons covertly.

VOA: standard.2009.10.28