Which of the following can wear away the solid rock of a cliff over time

What are two reasons for why a species might disappear from the fossil record?

Aflashlight battery is an example of a) potential energy b) kinetic energy c) thermal energy d) solar energy

Students in biology are studying the macromolecules of life. they used a calorimeter to determine the calories in various types of food. once the lab was completed, the students ate the left over food samples. monica commented that in just 6 or 7 "chews" of the saltine, it was gone; nothing but a sticky paste in her mouth. elaborate on what happened chemically while chewing the saltine. include the macromolecules present.