Why is it important for the body to recognize its own cells ?

It's important your body to recognize it's own cells.

Explanation: The Immune system is a great defense mechanism which it protects your body from bacteria and foreign invaders.  The immune system can make this distinction because all cells have identification molecules on their surface.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.

the answer is d. exposing corruption in the church