It seems unlikely that there is NO way to close that pit. Perhapsit must be a bug in this android version
the person who converted the game misunderstood how this
particular puzzle worked in the original. Somebody must
have tested the game to the extent that each of the four exits
from DDD is accessible.
Has anyone found a way to examine the data files of this game?
Edit: It just occurred to me that a likely misunderstanding
might be that a particular object needs to be presented to
the eye. I forget the exact circumstances. Is there some
object that might make sense?