We have a wide variety of substances, we should know how to check them if there are dangerous or not. There is acid or alkaline can consume, or not to be useful and harmless substance of knowledge.
Around us there are many types. We should know how to check those substances that are harmful or not. Acidity or alkalinity Can be consumed or This is to be And harm to our health.
Around us there are many different kinds. We should know how to check those substances that harm or acidic or alkaline, can consume or not as useful. And know the danger of substances.