COMPREHENSION CHECK (page 118)
1. Mark the correct answer in each of the following.
(i) Early man was frightened of
(a) lightning and volcanoes.
(b) the damage caused by them.
(c) fire.
(ii) (a) Fire is energy.
(b) Fire is heat and light.
(c) Fire is a result of a chemical reaction.
2. From the boxes given below choose the one with the correct order of the following sentences.
(i) That is fire.
(ii) A chemical reaction takes place.
(iii) Energy in the form of heat and light is released.
(iv) Oxygen combines with carbon and hydrogen.
(i) (ii) (iii) (iv) (ii) (iii) (i) (iv)
(iv) (iii) (ii) (i) (iv) (ii) (iii) (i)
WORKING WITH THE TEXT (page 119)
Answer the following questions.
1. What do you understand by 'flash point' of a fuel?
Ans:- The temperature at which a fuel catches fire or starts burning is called its ‘flash point’.
2. (i) What are some common uses of fire?
Ans:-Fire is normally used to cook food, generate electricity, warm our homes in the winter and diagnose diseases.
(ii) In what sense is it a "bad master"?
Ans:-If we use fire carelessly it goes sometimes out of control. If it is out of control it becomes a bad master. It can damage life and property.
3. Match items in Column A with those in Column B.
A B
(i) fuel coal, wood, cooking gas
(ii) oxygen air
(iii) heat lighted matchstick, burning coal, smouldering paper
4. What are the three main ways in which a fire can be controlled or put out?
Ans:-Three ways to control fire are
(i) We can take away the fuel very quickly,
(ii) We can prevent oxygen from reaching it,
(iii) We can remove the heat of the fire very quickly.
5. Match the items in Box A with those in Box B
Ans:- (i) To burn paper or a piece of wood, we heat it before it catches fire.
(ii) Small fires can be put out with a damp blanket.
(iii) When water is spread on fire, it absorbs heat from the burning material and lower the temperature.
(iv)A carbon dioxide extinguisher is the best thing to put out an electrical fire.
(v) Space left between buildings reduces the risk of fire.
6.Why does a burning candle go out when you blow on it?
Ans:-When we blow on a burning candle, we remove the hot air of its flame. And so the temperature of the flame falls lower than the flash points and it goes out.
7. Spraying water is not a good way of putting out an oil fire or an electrical fire. Why not?
Ans:-If we spray water on a burning oil it can float on the water and reach the sprayer and damage the person and property. We know that water is a good conductor of electricity so after spraying water on the electrical fire it can give an electric shock and the person may be killed.
8. What are some of the things you should do to prevent a fire at home and in the school?
Ans:-The things concerned with fire fighting must be kept ready all the time at home and at school to be control the fire very soon. Electrical wires and appliances must be arranged properly and insulated well.
WORKING WITH LANGUAGE (page 120)
Read the following sentences.
To burn paper or a piece of wood, we heat it before catches fire. We generally do it with a lighted match. Every fuel has a particular temperature at which it burns.
The verbs in italics are in the simple present tense. When we use it, we are not thinking only about the present. We use it to say that something happens all the time or repeatedly, or that something is true in general.
Find ten examples of verbs in the simple present tense in the text ’Fire: Friend and Foe’ and write them down here. Do not include any passive verbs.
Ans:- (i)Oxygen comes from air.
(ii) When the oxygen in the air combines with carbon and hydrogen in the fuel, a chemical reaction takes place.
(iv) When you blow on smouldering paper, it often bursts into flame.
(v) Fuel and oxygen do not make fire by themselves.
(vi) We generally do it with a lighted match.
(vii) Every fuel has a particular temperature at which it begins to burn.
(viii) We use it to cook our food.
(ix) It does not allow oxygen to reach the burning material.
(x) It absorbs heat from the burning fuel and lowers the temperature.
Fill in the blanks in the sentences below with words from the box. You may use the birds more than once.
Carbon, cause, fire, smother.
(i)Gandhiji’s life was devoted to the cause of justice and fair play.
(ii)Have you insured your house against fire?
(iii)Diamond is nothing but carbon in its pure form.
(iv)If you put too much coal on the fire at once you will smoulder it.
(v)Smoking is said to be the main cause of heart disease.
(vi)When asked any an ambitious writer whether he should put some fire into his stories, Somerset Maugham murmured, “No, the other way round”.
(vii)She is a carbon copy of her mother.
(viii)It is often difficult to smother a yawn when you listen to a long speech on the value of time.
3. One word is italicised in each sentence. Find its opposite in the box and fill in the blanks.
Spending, shut, destroy, subtract, increase
(i) You were required to keep all the doors open, not shut.
(ii) Pupil: What mark did I get in yesterday’s Maths test?
Teacher: You got what you get when you add five and five and subtract ten from the total.
(iii) Run four kilometres a day to preserve your health. Run a lot more to destroy it.
(iv) If a doctor advises a lean and lanky patient to reduce his weight further, be sure he is doing it to increase his income.
(v) The world is too much with us; late and soon, Getting and spending we lay waste our powers.(Wordsworth)
4.Use the words given in the box to fill in the blanks in the sentences below.
Across, along, past, through.
(i) The cat chased the mouse across the lawn.
(ii) We were not allowed to cross the frontier. So we drove along it as far as we could and came back happy.
(iii) The horse went past the winning post and had to be stopped with difficulty.
(iv) It is not difficult to see through your plan. Anyone can see your motive.
(v) Go along the yellow line, then turn left. You will reach the post office in five minutes.
SPEAKING AND WRITING (page 122)
1. Look at the following three units. First re-order the items in each unit to make a meaningful sentence. Next, re-order the sentences to make a meaningful paragraph. Use correct punctuation marks in the paragraph.
(i) and eighteen fire tenders struggled/ the fire began on Monday/ to douse the blaze till morning
Ans:-The fire began on Monday and eighteen fire tenders struggled to douse the blaze till morning.
(ii) in a major fire/ over 25 shops/ were gutted
Ans:- Over 25 shops were gutted in a major fire.
(iii) but property/ was destroyed/ worth several lakhs/ no casualties were reported.
Ans:- No casualties were reported, but property worth several lakhs of rupees was destroyed.
Paragraph: Over 25 shops were gutted in a major fire. The fire began on Monday and eighteen fire tenders struggled till morning to douse the blaze. No casualties were reported, but property worth several lakhs of rupees was destroyed.
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