what backs digital currency Knowledge graph

What is the only certainty in countless changes?What is iron logic?

What is the only certainty in countless changes?If it rises too much, it will fall, and if it falls too much, it will rise.

Those who delete posts and pictures are liars, and they can't be faked only when they are posted on the same day, because anyone with eyes can see it if it goes up or not.What is iron logic?What is iron logic?