Actually the correct answer is,Trench.
Definition of trench:
A long, narrow ditch,Dig a trench or trenches in (the ground).
As seen the meaning of trench now you know that is the correct answer.
Replace the sentence from "The Grand Canyon,as seen here,can be compared to a(n)_______under the earth's ocean."To"The Grand Canyon,as seen here,can be compared to a(n) trench(narrow ditch) under the earth's ocean.So the correct answer is A trench.
Ps,Bri <3
Plz give brainlyiest :)
