@Byunghack Oh,
Quote:Nobody knows for sure (that / what) the world will look like 20 to 25 years from now.
1. that or what
2. and i want to know the reason..
This is a combination of a statement and a question, which centrox alluded to.
When English speakers combine them the question form is removed as it is no longer a question.
How old are you? --> Nobody knows how old you are.
What is her name? --> I want/need/have to know what her name is.