Now-a-days in schools environment education is also provided to students. They form 'Eco clubs' to create awareness about the environment. As Radha is a member of the 'Eco club', she will be suggested to make beautiful dustbins (as use me) to collect garbage, organise small discussions and entertainment programmes regarding 'Save environment' .

(i) Synthetic fibre soaks less water, whereas natural fibre soaks more water.
(ii) Natural fibre.
(iii) Synthetic fibre.

The diagram will be as follows:

The possible reasons are as follows:
(i) The current is not produced by the given liquid and hence, bulb does not glow.
(ii) Connections are loose.
(iii) Bulb is fused.
(iv) Cells are used up.

When the free ends of a tester are dipped into a solution, then the liquid between the two ends allows the electric current to pass and the circuit of the tester becomes complete. Also, when the current passes through the tester, it establishes a magnetic effect and hence magnetic needle shows deflection. In other words, we can say that the solution is a good conductor of electricity, so the needle gets deflected.

(a) Polished wooden table As the surface is smooth, so there is a regular reflection through it.
(b) Chalk powder Since, the surface is not smooth or it is uneven, thus there is a diffused reflection through it.
(c) Cardboard surface As its surface is uneven, so it will produce a diffused reflection.
(d) Marble floor with water spread over it As marble floor itself is very smooth, besides this there is a layer of water on it which makes the surface for regular reflection.
(e) Mirror Since, the surface of mirror is smooth, thus it will produce a regular reflection.
(f) Piece of paper Since, the surface is uneven, thus it will produce a diffused reflection.

Differences between thermoplastics and thermosetting plastics are as follows:

Microorganisms or microbes are too small to be seen by naked eyes. They can be seen with the help of a magnifying glass or microscope.

Difference between regular and irregular reflection:

If 17 full grown trees are cut, we can obtain about one tonne of paper.

(i) Thermoplastics
(ii) Thermosetting plastics

The same kind of plants grown and cultivated on a large scale at one place is called a crop

(1) Cornea
(2) Iris
(3) Eye lens
(4) Ciliary muscles
(5) Sclera
(6) Blind Spot.

Nitrogen cycle.

(i)Our atmosphere has 78% of nitrogen gas. Certain bacteria and blue-green algae are present in soil that fix nitrogen.
(ii) They convert it into compounds of Nitrogen.
(iii) These compounds can be used by plants through soil.
(iv) Plants synthesize proteins and other compounds.
(v)Animals feeding on plants get these.
(vi)When plants and animals die, bacteria and fungi present in the soil decompose them and again convert into nitrogenous compounds.
(vii) Certain bacteria convert them into nitrogen gas, which goes back to the atmosphere.

The supply of water to crops at different intervals is called irrigation. Latest irrigation method help us to use water economically. The main methods used are as follows:
(i) Sprinkler system: This system is more useful on the uneven lands where water is available in smaller quantity. The perpendicular pipes, having rotating nozzles on the top, are joined to the main pipe lines at regular intervals. When the water is allowed to flow through the main pipe with the help of a pump, it escapes from the rotating nozzles. It is sprinkled on the crop as if it is raining. Sprinkler is very useful for the sandy soil.
(ii) Drip system: In this system, the water falls drop by drop just at the position of the roots. So it is called drip system. It is the best technique of watering fruit plants, gardens and trees. This system consists of a main pipe to which lateral pipes are joined. The specially prepared nozzles are attached to these lateral pipes. The nozzles are grounded just near the roots of the plants. It provides water to plants drop by drop. Water is not wasted at all. So, it is a boon in regions where availability of water is poor

(a) Organisms that cannot be seen with eyes alone are called microbes.
(b) Microbes are useful to humans in many ways. They help in the production of curd, cheese, in cleaning the environment, etc.
(c) (i) Lactobacillus bacteria.
(ii) Penicillium
(d) Diseases caused by microbes are polio, malaria, etc.
(e) Jasmine is attentive, intelligent and curious.