There are two major sources of energy that power the earth's environmental systems, these are SUN AND THE EARTH'S INTERIOR HEAT.
The heat energy from the sun is the one responsible for processing all the external processes that occur in the atmosphere, hydrosphere and on the earth surface.
The energy from the earth's interior is the one that is respondsible for powering the internal processes that produce earthquakes, volcanoes eruptions and mountain formation.
Hi your answer is A. TTAAG i hope this help's!!!
Answer is D) <span>Saliva changes the chemical composition of food
A enzyme is a catalyst for chemical reactions, meaning it either facilitates or initiates a chemical reaction. In this case, saliva uses enzymes to change the chemical composition of food into compounds that our body can easily process and turn into energy. </span>
