Science 'N' us-3 final - School Books Publishers India

16.ENVIRONMENT AND POLLUTIONExerciseA. Answer the following questions :1. What do you mean by environment?Ans. Every living and non-living thing around us makes our environment.Environment includes plants, animals, human beings, rivers, ponds,lakes, earth, soil, water, air, etc.2. Define pollution.Ans. Addition of harmful substances into air, water, land, etc is calledpollution.3. What are the main causes of water pollution?Ans. Water pollution is caused due to the following reasons :(i) Throwing dirty water from houses into rivers.(ii) Throwing harmful wastes from factories into rivers.(iii) Washing clothes on river and pond banks and bathing of animalsand people in them.4. Write the main causes of noise pollution.Ans. Noise pollution is caused due to the following reasons :(i) Loud noise coming from motor vehicles like cars, buses, truckscauses noise pollution.(ii) Loudspeakers also causes noise pollution.5. How can you reduce pollution? Write any two ways.Ans. (i) Do not bathe or let animals bathe in rivers.(ii) Plant more and more trees.B. Choose the correct word from side box and fill in the blanks :1. Bathing of animals in rivers/ponds causes water pollution. plant2. Smoke produced by cars, buses, etc causes air pollution. smoke3. Excessive use of chemicals and fertilizers causes landpollution.chemicals4. We should plant more and more trees. clean5. We all want to live in clean and hygienic environment. fertilizersbathingC. Write :1. Two effects of air pollution :(a) eye irritations(b) lungs infection2. Two diseases caused by water pollution :(a) cholera(b) jaundice3. Two effects of land pollution :(a) damage of plants(b) killing of small creatures4. Two effects of noise pollution :(a) deafness(b) tensionHorizon Press70Science 'n' Us - 1 to 5