I’m not sure but it might be the third one
Answer: Mouth.
Explanation:
The mouth is known to be performing both the tasks of chemical digestion and mechanical digestion.
The food is ingested through mouth and the teeth perform the process of mechanical digestion by breaking down the food particles into smaller particles.
Then the saliva gets mixed into the food and the enzymes(amylase) present in the saliva helps in the digestion of carbohydrates.
So, mouth is the organ that performs the process of both mechanical and chemical digestion.
Solving problems with science means that to solve the problem the scientific method is used. This method includes observing, research, hypothesis , test and conclusion with a help of lot high level theory.
Without science there is not strict process to follow in order to resolve the problem end get to a solution.
No, because the immune system is already battling with the virus or disease