(i) Shearing
(ii) Scouring,
(iii) Sorting
(iv) Fibre spinning,
(v) Dyeing
(vi) Rolling intp the yarn

The black sheep in the poem seems to have wool on almost all the parts as it in the poem, it offers wool enough to fill three bags full.

We will put a drop each of hydrochloric acid, sodium hydroxide and sugar solution on the turmeric indicator. The liquid which changes the colour of turmeric indicator to red is basic in nature that is sodium hydroxide. Now, we will put a drop of sodium hydroxide on a drop of each of the other two liquids separately.
After that, we will put the drops of their mixtures on turmeric indicator. The drop which will change the colour of the turmeric indicator to red contains sugar solution.
This is because the mixture of base and the neutral solution is basic in nature. On the other hand, the drop which will not change the colour of turmeric indicator contains hydrochloric acid because hydrochloric acid reacts with sodium hydroxide forms a neutral solution.

(a) We take an antacid tablet such as milk of magnesia to neutralises the excessive acid released in the stomach.
(b) When an ant bites, it injects the formic acid into the skin. The effect of acid can be neutralised by applying calamine solution that contains zinc carbonate.
(c) The factory wastes contain acids if they are allowed to flow into the water bodies, the acid will kill fishes and other organisms. The factory wastes are thus neutralised by adding basic substances.

Distilled water is neither acidic nor basic. When we test its nature through litmus paper strips, we have found neither red nor blue changes in colour which verifies its neutral nature.

Differences between acids and bases are as follows:

(A) Eggs of silk moth on mulberry leaves
(B) Silkworm
(C) Cocoon
(D) Cocoon with developing moth.

The larva hatched from the eggs of silk moth are known as caterpillar.

The larva (or caterpillar) of a silk moth makes the silk fibre.

Two gaseous pollutants are nitrogen dioxide (NO₂) and sulphur dioxide (SO₂).

When hydrochloric acid reacts with sodium hydroxide solution, then sodium chloride salt is formed.

Turmeric stain on white shirt is turned to red when it is washed with soap because the soap solution is basic in nature.

The solutions or substances which do not change the colour of either red or blue litmus paper are neutral.

The wool is obtained from the hair of sheep in the following steps:
Step I-Shearing: The fleece of the sheep along with a thin layer of skin is removed from its body. Machines similar to those used by barbers are used to shave off hair. Usually, hair removed during the hot weather.
Step II-Scouring: The sheared skin with hair is thoroughly washed in tanks to remove grease, dust and dirt.
Step III-Sorting: The hairy skin is sent to a factory where hair of different textures are separated or sorted.
Step IV-The small fluffy fibres, called burrs are picked out from the hair. The fibres are scoured again and again and dried. 
Step V-Fibres can be dyed in various colours. 
Step VI-The fibres are straightened, combed and rolled into yarn. The long fibres are made into wool for sweaters and the shorter fibres are spun and woven into woollen clothes.

(a) Neha's mother took a thread of natural silk fabric and another thread of artificial silk fabric and burn them separately. The thread which burns giving a smell of burning hair will be natural silk (or pure silk). The thread which burns giving a smell a burning paper will be an artificial silk.
(b) Yes, pure silk saree is more costly than an artificial one.
(c) Neha's mother is intelligent and knowledgeable.