Which of the Following Statements Are True of the Digestive

Which of the following statements are true of the digestive processes (Select all that apply) ?

A) Chewing and the churning of the stomach are the only forms of mechanical digestion.
B) Chemical digestion requires enzymes,each of which is specific for one type of food.
C) An enzyme that requires a pH of 2 usually will not work at a pH of 8.
D) Mechanical digestion is helpful because it increases the surface area of food for enzymes to function efficiently.