The heart<span> is at the centre of your circulatory </span>system, which is a network of blood vessels that delivers blood to every part of your body. Blood carries oxygen and other important nutrients that all body organs need to stay healthy and to work properly. In other words, it supplies oxygen and nutrients to our bodies by working with the respiratory system<span>. At the same time, the </span>circulatory system<span> helps carry waste and carbon dioxide out of the body. Hormones — produced by the endocrine </span>system<span> — are also transported through the blood in the </span>circulatory system<span>.
The statement water is easily polluted..... is true. Water is pretty much the world's best solvent. So even toxic substances are easily dissolved in it and when that happens they pollute the water.
