pollution of air and water 10-08-20

When air is contaminated by unwanted substances which have a harmful effect on both the living and the non-living, it is referred to as ___________pollution.

• water

• air

• sound

• soil

The substances which contaminate the _________ are called air pollutants.

• sound

• air

• water

• soil

Many ___________ problems are caused by air pollution

• digestive

• respiratory

• nervous

• bone

________________ is produced from incomplete burning of fuels such as petrol and diesel.

• carbon dioxide

• carbon monoxide

• carbon trioxide

• carbon tetraoxide

Increasing levels of greenhouse gases like __________________ are leading to global warming.

• carbon dioxide

• carbon monoxide

• carbon trioxide

• carbon tetraoxide

Water which is purified and fit for drinking is known as____________ water.

• potable water

• pot water

• mud water

• dirty water

_________ is a precious natural resource.

• water

• gold

• soil

• air

If the vehicles registered in Delhi are lined up one after the other, the total length would be nearly equal to the combined lengths of the two longest rivers in the world,_____________ and________

• nile

• amazon

• both a and b

• brahmaputra

Boojhoo remembers seeing a thick fog-like layer in the atmosphere, especially during winters. This is smog which is made up of ________ and__________

• smoke

• fog

• both a and b

• only smog

Other kinds of pollutants are chlorofluorocarbons (CFCs) which are used in refrigerators, air conditioners and aerosol sprays

• refrigerators

• air conditioner

• aerosol sprays

• all the above