The finely cut wooden boards from the wood are layered one above the other to make plywood. This is a kind of composite wood.

Softwoods come from gymnosperm (non-flowering plants) trees. Certain angiosperms also yield softwood.

i) Do not pour leftover oil, old medicines or waste down the drain or into, the toilet.
ii) Reduce the use of chemical pesticides and fertilizers to grow crops.
iii) Use waste water for garden in home.
iv) Do not litter or dump waste- always use- a waste bin.

i) First try to reduce waste, then recycle the rest.
ii) Always use a waste bin and never litter.
iii) Do not burn waste, the ash mixes easily with soil.

The paste like substance is called adhesive. It is commonly known as glue, mucilage, or paste: The substances applied to one surface, or both the surfaces of two separate items that binds them together and resists their separation are called adhesives.

i) Fertilizers are organic or inorganic materials that we add to the soil to provide one or more nutrients to the soil.
ii) Fertilizers given to plants can be classified into two. They are organic and inorganic fertilizers.

Evaporation: Water from oceans, lakes, ponds and rivers evaporates due to the heat of the sun.

Water is a transparent, tasteless, odourless and nearly colourless chemical substance.

i) Magnetite was the ore with attracting property found in that region.
ii) Magnetite are natural magnets. They are called magnetic stones.

Timbers are used to build houses and make into furnitures.

Neem tree, Tulsi, Amla.

(a) Loud Speaker - Noise pollution
(b) Plastic - Land pollution

Ecosystem is a community of living and non-living things that work together.

(i) Cement becomes hardened when it is mixed with water.
(ii) It is necessary to control the rate of hardening.
(iii) so that, Gypsum is added to cement at the final grinding process.

i) In making black board chalks.
ii) In surgery for setting fractured bones.
iii) For making casts for statues and toys etc.
iv) In construction industry.

There are two types of rain water harvesting
1. Collecting water from where it falls.
2. Collecting rainwater by constructing bunds.

When the air around the clouds is cool then only it will rain. That is the reason why it doesn't rain daily.

Parts of a Computer:
(i) Input Unit
(ii) Central Processing Unit (CPU)
(iii) Output Unit

The eye has three main parts namely cornea, iris and pupil

Digestion and absorption of food done by digestive system.

Cytoplasm is called as "Area of movement"

(i) Cell membrane
(ii) Cytoplasm
(iii) Nuclecus are the essential components of a cell.

The roots of a plant take up air from the spaces between the soil particles.

If we remove the fish from the aquarium and keep it in a dark place with green plants,
(i) they can't have sunlight and
(ii) have no CO₂ from the water produced by fish as they breathe.
(iii) Simply say, there is no possibility for photosynthesis to make their food.

Changes which take place over a long period of time are known as Slow changes.

Yes, we can make a candle doll from candle wax. It is a kind of physical change.

The Iron chain is the conductor from the above figures.

(i) The measurement of warmness or coldness of a substance is known as its Temperature.
(ii) SI unit of temperature is kelvin

(i) The Water heater
(ii) Iron box
(iii) Electric kettle etc.

Printers and Monitors are output devices.

Windows and Linux are operating software

The tail of the bird helps to change the direction of the movements.

The birds catch their pray with their beaks and with a pair of claved feet

The settling down of heavier component of a mixture when allowed to remain undisturbed for some time is called sedimentation.

Lemon juice is a mixture because it is a miture of lemon extract, water and sugar.  This is a mixture though the amount of sugar and water added is different we know that, in a mixture the components are mixed in any proportion.

The green leaves prepare food by the.process of photosynthesis.

The area where a particular organism actually lives is called its habitat.

Charles Babbage and Augusta Ada Lovelace are the pioneers of computer.

A balanced diet is one which contains adequate amount of al the necessary nutrienrs required for healthy growth and activity.

1 millimetre < 1 centimetre < 1 Metre < 1 kilometre.

Both A and R are correct and R is the correct explanation for A.