Garbage - is the food waste from kitchen, any discarded or useless material. Solid waste management is also known as garbage management.

Wheeled vehicles are used to carry garbage and take it to the low lying areas. Hence, garbage truck is the correct answer.

Residential waste includes plastic, food waste etc. Industrial and municipal corporations are other sources which produce waste.

Organic waste - organic means related to living things. Organic wastes include human waste, animal waste, oil, urea (urine), fruit & vegetable waste. Organic waste does not have to be thrown away. It may be reused as a fertilizer through a process called compositing & the mixture is known as compost. Composting - is done by putting organic waste in a bin & leaving some space for air to circulate. As heat and steam build up, the waste decomposes over time into a nutrient rich substance called compost. The compost is then applied to plant as manures. Hence (2) is the correct answer.

Wastes can be classified into three types: Biodegradable waste - It is the waste that will decay and decompose into the soil. All waste derived from living matter is biodegradable. For example, food waste such as fruits and vegetable peels, meat and bones, leaves, flowers, paper, etc. Non-biodegradable waste – It is the waste that will not decay and decomposed into the soil. This includes plastics (for example, bags and packaging material), metals (cold drink cans) and glass (old bottles, broken glass pieces, bulbs), etc. Toxic (poisonous) Waste - Wastes such as medicines, batteries, dried paint and dried shoe polish, etc. are toxic. These are much more difficult to dispose.

Hence, option (2) is the correct answer.

Landfills are the structures built into or on the top of the ground in which garbage is dumped from the surrounding environment. It is the oldest form of waste treatment.

Biodegradable waste can be recycled by the method of composting. It is a natural process that recycles the nutrients in the waste to yield manure. Manure obtained is very rich in nutrients and is an excellent medium for growing plants.

Decomposers are the micro-organisms which act on the dead remains and waste products of animals and plants. They breakdown the complex substances into simpler ones that mix into the soil and are used up by the plants.

If the rotting is complete, the colour of the garbage turns black and there will be no foul smell. If the garbage has not changed at all or there is foul smell, it means garbage is not rotten completely. If the rotting is not complete, cover the bags again with soil and allow bacteria to act on them.

Hence, option (2) is the correct answer.

Biodegradable waste e.g. fruits & vegetable peels, meat & bones, leaves, flowers, paper etc can be recycled by the method of composting. It is a natural process that recycles the nutrients in the waste to yield manure or compost. Manure is a non-poisonous substance which is very rich in nutrients and is an excellent medium for growing plants.

There are two types of wastes: (i) Biodegradable (ii) Non-biodegradable Biodegradable waste can be decomposed by bacteria. Plastics can be recycled. The recycling rate for plastic bottles is 57% and for pots, tubs and trays, it is 30%. Glass is one of the few materials that can be recycled infinitely without any loss in strength, purity or quality. 

Vegetable peels, hay, animal excreta are all biodegradable waste and hence, can be converted into useful products by the process of composting. It is a natural process that recycles the waste to yield manure or compost. The manure is rich in nutrients and is an excellent medium for growing plants. Apart from being clean, cheap and safe, composting also reduces the amount of garbage. Composting is also done by using earthworms. This type of composting is known as vermicomposting.

Rottening - means decaying of the material. It is a natural breakdown of complex organic compounds into simpler substances. Rottening or decay occurs in dead plants & animal tissues. i.e. Rottening occurs in biodegradable waste. All the waste derived from living matter is biodegradable. Leather - is animal skin that has been chemically modified to produce strong flexible materials. Therefore, it is a biodegradable waste. Coconut - is a hard shelled fruit containing juice. Therefore, coconut is also biodegradable waste material hence both leather & coconut can be rotten down.

Radioactive element is not a household waste.

DDT is a chemical which is used for killing insects and synthetic fiber is  not an organic material. Hence these cannot undergo rotting. Therefore, (3) is correct answer.

Raw banana is the odd one out as it is an example of biodegradable waste whereas plastic toy, glass bottle, polythene are the examples of non-biodegradable waste. Biodegradable waste - can decayed and mix with the soil. All waste derived from living matter is biodegradable. Raw banana is taken from plants and plants are living. On the other hand plastic, glass, polythene are not derived from living matter and are therefore non-biodegradable waste that cannot be decayed and mix with the soil.

Wrapping waste in polythene bags is the correct answer for this question as polythene bags are non-biodegradable waste.

Four different coloured rubbish bins: (a) Organic waste (plants and animal waste) – Green (b) Paper – White (c) Metal or glass waste - Blue (d) Hazardous – (for batteries, etc) – Red

Burning of leaves and husks (biodegradable wastes) produce smoke. Smoke is a mass of tiny particles in the air that rises up for when something is burned. Hence, smoke is the correct answer.

 Four different coloured rubbish bins: (a) Organic waste (plants and animal waste) - Green (b) Paper - White (c) Metal or glass waste - Blue (d) Hazardous - (for batteries, etc.) - Red Hence, the correct answer is blue.

Burning of garbage produces smoke and poisonous gases, which are injurious to living beings. Hence, burning of garbage should be banned as it pollutes the environment.

Biodegradable waste that can be decayed & get mix with the soil, can be recycled by the method of composting. It is a natural process that recycles the nutrients in the waste to yield manure or compost. Manure obtained is very rich in nutrients & is an excellent medium for growing plants. Apart from being clean, cheap & safe, composting also reduces the amount of disposable garbage.

After loads are deposited, compactors or bulldozers can spread and compact the waste on the working face. These are converted into parks.  

Biodegradable waste for e.g. food waste such as fruit and vegetable peels, meat & bones, leaves, flowers etc can be recycled by the method of composting. It is a natural process that recycles the nutrients in the waste to yield manure or compost. The manure is very rich in nutrients and is an        excellent medium for growing plants. Vermi-composting is a method of composting where compost is made from biodegradable waste with the help of a type of earthworms called red worms. The red worms eat biodegradable kitchen waste & convert it into compost, which is an excellent manure.

There are two types of waste material: Biodegradable - are useful waste material as such waste that can undergo decaying & mix with the soil. Such waste can be recycled by the method of composting. It is a natural process that recycles the nutrients in the waste to yield manure or compost. The manure obtained is very rich in nutrients and is an excellent medium for growing plants. Non-biodegradable - are non-useful waste material. Such wastes cannot undergo decaying & do not get mix with the soil & hence no useful products like manure can be obtained by them. Hence, waste should be dispose off separately as biodegradable waste and can easily undergo decaying & products obtained by decaying of biodegradable wastes are useful.