Factories and industries should be situated far away from residential areas.

Oxygen and carbon dioxide are required in respiration and combustion.

Combustion or burning is a chemical process.

If both, respiration and combustion, continue to operate in nature, the air will change appreciably and this will result in an imbalance in nature.

Plants also respire like humans to release energy.

Water vapour is essential for running the water cycle in nature.

Atmosphere contains about 0.3 percent of carbon dioxide.

The level of nitrogen in the atmosphere also plays a role in determining the global temperature.

Plants and animals help each other through exchange of gases in the atmosphere.

What happens when carbon dioxide reacts with lime water?

Fertilisers can be replaced with which of the following?

Ozone layer present in the earth’s stratosphere is responsible for protecting us from which harmful rays?

Which of the following does not trap heat energy of the sun?

Fossil fuels are formed from the remains of which of the following?