1: You throw away the outside and cook the inside. Then you eat the outside and throw away the inside. What did you eat?
corn as answered...
2: I have holes in my top and bottom, my left and right, and in the middle. But I still hold water. What am I?
sponge..as answered...
3: The man who invented it doesn't want it. The man who bought it doesn't need it. The man who needs it doesn't know it. What is it?
Normally this is worded "the man who makes it doesn't want it", but a coffin
4: I am mother and father, but never birth or nurse. I'm rarely still, but I never wander. What am I?
A country. Russia is known to be referenced to as 'The Motherland' as is Brittain and a few others. Germans were known to call Germany the "Fatherland" during WW2 (don't know if they still do). There will always be some form of unrest in a country ("...rarely still...") but it will never suddenly be in a different area than it is ("...never wander...")
Okay, how close am I on that last one?
