Water helps in formation of soil in following ways
(i) Water causes ‘wear off’ of rocks over a long period of time.
(ii) It also causes the rocks to rub against other rocks creating small particles which are
taken away downstream and deposited as soil.
(iii) Water expands on freezing in crevices of rocks and cracks rocks into smaller pieces. 

Fertile soils are rich in organisms that decomposes dead organic matter forming humus. Humus gives minerals, absorbs water and makes soil porous.

Farms in hills have steep slopes. There is always a risk of top soil being washed away by rainwater because of steep slope. Steps are made to prevent soil erosion. Hence, step farming is common in hills.

In root nodules nitrogen fixing Rhizobium bacteria are present which increases the soil fertility.

The fossil fuels like coal and petroleum contain small amounts of nitrogen and sulphur. When fossil fuels are burnt, it produces oxides of nitrogen and sulphur. These gases cause inhalation problems and in presence of rain forms acid rain. Burning of fossil fuels also increase the amount of suspended particles in air that reduce the visibility.

Water pollution can be caused by addition of
(i) undesirable substances like fertilizers and pesticides or any poisonous substances.
(ii) sewage directly entering a water body.
(iii) hot water from the power plant that increases the temperature and reduces the dissolved oxygen in water thus killing the aquatic organisms.
(iv) industrial effluents or radioactive substances in water body. We can take following measures to check water pollution
(i) The sewer lines should not be directly connected to the water body.
(ii) We should not throw our garbages or domestic waste in the water body.
(iii) Prevent dumping of toxic compounds in the water bodies.
(iv) Washing of clothes should be avoided near water bodies as it adds lot of detergents to it.
(v) Plant trees near the banks of the river to check soil erosion otherwise erosion leads to siltation of water body. 

Infra-red radiations in sunlight pass through the glass and heat the interior of the car. The radiation emitted by upholstery and other inner parts of the car cannot pass out of the glass, so the heat trapped inside raises the temperature of the interior. This is because glass is transparent to infrared radiation from the sun having smaller wavelength than that emitted by the interior of the car which are of longer wavelength to which the glass is opaque

Dust remains present in air as suspended particles can cause allergy and other respiratory diseases. It also affects plant growth, by covering stomata on leaf surface. It acts as the carrier of toxic compounds like heavy metals.