The resulting erosion at the base of a waterfall can be very dramatic, and cause the waterfall to "recede." The area behind the waterfall is worn away, creating a hollow, cave-like structure called a "rock shelter." Eventually, the rocky ledge (called the outcropping) may tumble down, sending boulders into the stream
Study island but you will have to pay or if younr still in school ask your teacher for a username and password OR.... Try dictionary.com. It has grammar, meaning, and part of speech.
Answer:
Viscosity of magma depends mainly on composition, temperature, and gas ...
The arrival on the surface of magma that has lost its gas ..... It is a 0-to-8 index of increasing explosivity.
