Good Riddles

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?

Question: I may have come in last but I'm still on top. What game are we playing?

Question: What type of chair is electric, you can't get out of it on your own, but if someone helps you get out you're not dead?