Hardest Riddle Ever

[eachdraidh]

What goes up and down the stairs without moving?

Give me food, and I will live; give me water, and I will die. What am I?

What goes around the world but stays in a corner?

 

[streat]

YEAh,that the answer!!!Well,i think your the 5 percent of stanford graduates!!!HaHa,just kidding,nice guess btw.......