Answer:
I can travel from there to here by disappearing, and here to there by reappearing.
When it comes in, From sea to shore, Twenty paces you'll see, No less, no more.
As soft as silk, as white as milk, as bitter as gall, a thick green wall, and a green coat covers me all.
The more holes you cover the lower it goes.
What is the only letter in the alphabet that does not appear anywhere on the periodic table of elements?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.