"How did you know about the existence of the network in America?"
Everybody knew I'd told the truth about the existence of the island.
There is data about its existence even before the 16th century.
But for the time being, nobody should know about my existence.
I'm sure you didn't want me to know about their existence anyway.
However, the book does not make it clear where the information about the existence of the letters came from.
Not this letter, perhaps, but probably he knew about the existence of letters in general.
How could you argue about the existence of a rock?
Because of this, many years were passed without knowing about their existence.
It has also helped her resolve the questions she once held about the existence of a higher power.