Q. 233. Write the importance of ozone layer.
Q. 234. How carbon monoxide is produced in at mosphere? How is it harmful to man?
Q. 235. What is air pollution? Write the processes that cause air pollution.
Q. 236. What is smog? Name any two disease caused by smog.
Q. 237. What are occupational hazards. Write their symptoms.
Q. 238. Write the major pollutants of water and their sources.
Q. 239. Distinguish between biodegradable and non-biodegradable wastes. giving examples.
Q. 240. Which of the following are biodegradable?
Aluminium wire, aluminium foil, tea-leaves, synthetic fibre, wool, paper, ball point per refill, hay, polythene bags, animal bones, iron nails, plastic mugs, leather belts, DDT
Q. 241. How is ozone layer formed?
