Definitely do not lift the ban on ivory, it will drive the species to near extinction again. Elephant numbers should be controlled but what has ivory got to do with it? It is a barbaric trade and should be banned permanently.
Elephants and mice are natural enemies.
From the context we do not know whether or not mice and elephants are natural enemies, therefore the statement is neither definitely correct nor definitely incorrect
( z1 have-rel-role :ARG0 ( z2 elephant ) :ARG1 ( z3 mouse ) :ARG2 ( z4 enemy :ARG1-of ( z5 natural ) ) )