The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
Answer:
D
Explanation:
Bacteria, air, animals, plants
Answer:
They may change due to environmental changes. for example, if a cactus suddenly experiences a drought, it may change to become better at holding water than before. if it suddenly experiences large amounts of rainfall, it may change to release more water, etc.
Forest fires promote regrowth, clear cut has to be replaced
