Fill in the blanks with suitable words. Air is essential (a) — life. We breathe (b) — oxygen from the air. Clean air is important for health, but nowadays air pollution is (c) — major issue. Smoke from factories and vehicles mix (d) — the air. This polluted air harms not only humans (e) — also animals and plants. We should plant more trees (f) — they absorb carbon dioxide. Government should make strict laws (g) — prevent air pollution. Every person should be responsible (h) — keeping the environment clean. Let us all work (i) — cleaner air and healthier life (j) — future.