Good Riddles

Question: I can be one, I can be two. I can be Open, Closed, Empty or Full. I can be Bare, but never a Bear. What AM I??

Question: When you close it, you see mysterious and funny looking images. But if you open it, the mysterious images are gone. What Am I?

Question: in all of written history I won't show up at the end of a sentence but I will be there in the end . . .

Question: A pond with dimension of 6m by 3m wil be filled of water lilies at exactly 30 days. Each day the number of water lilies will be doubled. First day 1, second day 2 etc... On what day it will fill half of the pond?

Question: I can fall, I can sink, I can lay underground I can go on, I can go off, I can go up, but not down If you want to stop me: I give you 2 choices The same as Neo had What am I?