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.
Answer:
Mass is how heavy something is, volume tells you how big it is, and density is mass divided by volume. you can usually think of weight and mass as the same thing.Volume is the size of an object, and mass is its weight. Density is calculated by dividing an object’s mass by its volume. Density is sometimes used to describe other quantities divided by volume, such as energy density.
Theories explain phenomena, whilst laws are generalizations which characterize them.