Is this the question or what
Answer:
Your digestive system absorbs water and nutrients from the food you eat. Your circulatory system carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells are eliminated by your respiratory system, your excretory system, and your skin.
Explanation:
the answer is a because if the model is based on experimental data it wont be good unless it has been tested.
Answer:
1. it's difficult
2.more harder
<u>Explanation</u><u>:</u>
lt have sense
