5. Fill in the blanks with appropriate words:

Air and water are two important (a) - of the environment. These elements are (b) - for life on earth. They are often (c) - in many ways. Air is polluted mostly by (d) - and water by different kinds of waste and (e) - If we want to live a (f) - life, we should (g) - the pollution of the environment. Total prevention may be (h) -, but we can certainly (i)- pollution by raising (j) - among people.