Choose the word that correctly completes the sentence.
LIt's hard to believe, but the Grand Canyon was created as a result of _ Over millions of years, the flow of
the Colorado River gradually wore away the dirt and rocks, carving the canyon into the earth.
2. Many years ago, men and women made shoes by hand. They cut the leather and stitched the fabric together. Now,
however, the process is almost entirely _
and done by machines.
3. The lion crept up on its _ an unsuspecting zebra. When the lion pounced, the zebra tried to escape, but
the lion quickly ran it down.