Use appropriate sentence connectors in the blank spaces of the following passagE-

Air is an important element of our environment. (a) _____, clean air is essential for our lifE- (b) _____, air is polluted in many ways. (c) _____, one thing that pollutes air is smokE- Smoke is produced from different sources. (d) _____, we make fire to cook food and it creates smokE- (e) _____, buses and trucks plying in the roads emit smokE- (f) _____, the burning of coal in the railway engine also produces smokE- (g) _____, the mills and factories also produce a huge amount of smokE- (h) _____, we melt tar for road constructions which produces black smokE- (i) _____, all these smokes mix with the air and pollute it. (j) _____, smoke from different sources is causing serious harm to our environment.