Answer:
Your respiratory system takes in oxygen from the air. It also gets rid of carbon dioxide. 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.
Explanation:
The answer is b. I am not sure exactly how to explain this, but it fits in much better with that question. I hope this could help you!
The properties of the original elements are completely changed.
For example, in the compound called "iron(II) sulphide", it is composed of iron and sulphur, that are chemically combined together. The element iron is attracted to magnets. Meanwhile, iron(II) sulphide is not attracted to magnets.
Another example is where sulphur has a yellow colour, but iron(II) sulphide has a brownish colour. As we can see, even the physical properties (colours) are completely different.
Therefore, the properties of the original elements are completely changed when they're combined into compounds.
