The correct answer is C the suns energy from the earth
the answer is A.) the moon is orbiting the earth once per month
its the only logical answer, the others are either impossible or illogical
I can answer your question if you have a picture or a writing, your welcome.
The answer in this question is just easy and simple, since there are lots of <span>different enzymes being secreted in the stomach (the enzymes are made of protein and can be denatured by alternation of pH, each of these enzymes required to have a specific optimal pH. </span>