CFCs stand for chlorofluorocarbons.
CFCs are used in refrigerators, air conditioners and aerosol sprays.
CFCs are considered as pollutants because these are depleting the useful ozone layer of the upper atmosphere.
CFCs released into the air, go up and ultimately reach high into the atmosphere where the protective ozone layer exists. The chlorofluorocarbons react with ozone gas of ozone layer and destroy it gradually. This allows the harmful ultraviolet rays of the sun to reach the earth and cause damage.

(a) It is recommended to stop the vehicle engine at the red light signals to minimise the emissions of poisonous gases like CO, NO, etc from the automobile exhaust.
(b) With the vehicle engine ON, the incomplete combustion of fuel will take place with release of gases like CO.
(c) The government is trying to make people understand the need for reducing environment pollution and the small steps that they can take for environmental protection.
(d) Yes, I will support the message. It is for the common good.
(e) Arjun is keen learner, strong observer and responsible.

We should plant trees and nurture the ones already present in the neighbourhood. This is to
(i) Reduce air pollution Plants clean the air. They also reduce dust particles in the air. This will lower down the pollution level
(ii) Minimise global warming The greenhouse gas CO₂ is responsible for global warming. Plants utilise CO₂ for making food and give out O₂, Therefore, planting more trees will reduce the CO₂ in atmosphere and thus global warming will be in control.

(a) Various sources of water pollution are classified as point sources and non-point sources.
(b) The sources or places of pollution which are easily identifiable are point sources of water pollution.e.g. factories, power plants, etc.
(c) Agricultural run-off and acid rain are non-point sources of water pollution.

The Ganga is the Indian holy river that is amongst the ten most endangered rivers list of WWF. The water has been highly polluted because the towns and cities through which the river flows, throw huge quantities of garbage, untreated sewage, dead bodies and many other harmful things, directly into the river. In fact, the river is dead at many places where the pollution levels are extremely high.

Across:
(i) Chlorofluorocarbons
(iii) Carbon monoxide
(iv) Pesticide
Down:
(ii) Ozone
(iv) Oxygen
(v) Cholera
(vii) Ganga

Pollutants in air are discolouring white marble of Taj Mahal. The Mathura Oil Refinery near Agra as well as various industries in and around Agra are emitting gaseous pollutants such as sulphur dioxide and nitrogen dioxide into the air which cause acid rain. Acid rain corrodes the marble (CaCOJ of the monuments Suspended particulate matter such as the soot particles emitted by Mathura Oil refinery has contributed towards the yellowing of the Marble. The Supreme Court of India ordered all the industries in Agra area to switch over to cleaner fuels like CNG and LPG to reduce air pollution.

Air gets polluted by many reasons. Few of them are as follow:
(i) Vehicles produce high level of pollutants like carbon monoxide, carbon dioxide, nitrogen oxide, smoke etc. These are very poisonous gases. Burning of fuel from vehicles also produces pollution.
(ii) Many industries are also responsible for causing air pollution. Petroleum refineries release polluted gases such as sulphur dioxide, nitrogen dioxide etc. They cause respiratory problems, including lung damage.
(iii)Other kinds of pollutants are CFCs which are largely used in refrigerators, air conditioners and aerosol sprays. Those protect us from ultraviolet rays of the Sun.
(iv) Some human activities like forest fire, burning of fire wood, cow dung cakes, burning of chaff etc. cause air pollution.
(v) Some natural phenomenon like fast dust storms, volcanic eruption produce smoke and dust particles

If my sister and neighbour are wasting the precious water, I agree with you because we have very less amount of potable water on the earth. As population increases there will be scarcity of this. To control this situation we must talk with them regarding importance of water and tell them alternative methods for their tasks, such as using bucket to take bath and clean their vehicles

Water is an important and precious resource. Nowadays it is polluted with many harmful substances such as sewage, toxic chemicals, silt etc. which get mixed with water. Many industries discharge harmful chemicals into rivers and streams. To avoid these situations many compulsory rules must be obeyed as various physical and chemical processes in the sewage treatment plants must be done before discharging sewage into the water bodies. At our individual level we should consciously save water and do not waste it. Reuse and Recycle should be our Mantra.