Fill in the blanks with suitable words. Pollution is a serious threat (a) — our environment. It affects air, water, and soil. (b) — pollution, life on earth is in danger. Air pollution results (c) — vehicles and factories. Water pollution is caused (d) — waste materials. Soil is also polluted (e) — pesticides and plastics. To stop this, awareness must be spread (f) — all levels. We must keep waste (g) — proper bins. The government should make laws (h) — prevent pollution. Students can play a role (i) — tree plantation and clean-up drives. Let us all take steps (j) — save nature.