Safe is the best option but it could also be wary or even rash as well but it's more likely to be safe and if that's not the correct word choice then it's a safe bet wary is the correct possible alternative hope this helps you out!
The answer is: the book will bear witness to events that must be known.
"Night" is an autobiographical novel by Elie Wiesel, who accounts his struggle as a prisoner during the Holocaust. He desires to make sure the world acknowledges what happened in concentration camps as he narrates how crude society was and how inhuman even prisoners became towards one another - mostly attemping to survive themselves.
The participle is "digging." Most participles end in -ing. It modifies "man", describing what the man is doing.
It is valiant. Valiant: possessing or showing courage or determination.
