Translate the sentences. Determine the function of the infinitive.

 

1. The earliest organic halogen compound to be used as a chemical extinguisher was carbon tetrachloride (СТС).

 

2. To use pumps to their maximum efficiency the firefighter must have basic knowledge of hydraulics.

 

3. What helped them reduce the hazard of the ignition source which couldn’t be removed from the dangerous area for a long time, was the inert gas.

 

4. It is necessary for an optimum vaporizing liquid extinguisher to have maximum combustion interference.

 

5. The combustion leading to flame propagation is known to be a chain reaction.

 

6. To extinguish a fire it is sufficient to reduce the oxygen content below the level that will support combustion.

 

7. Before extinguishing a fire firefighters should try to decide which agent to use.

 

8. It is easier to prevent a fire than to extinguish it.

9. To reduce the oxygen content some inert gases should be used.

 

10. Every hazard needs to be considered separately.

 

Write the following sentences in another way, beginning as shown. Use the underlined word in your sentences.

 

Example: It is considered that water is the most common extinguishing medium.

Water is considered to be the most common extinguishing medium.

 

1. It is said that modern dry powders are as complex as vaporizing liquids. Dry powders___________________________________________________

2. It seems that he has chosen the most suitable extinguishing medium.

 

He___________________________________________________________

 

3. It is known that volatile liquid compounds of the halogen have great fire extinguishing properties.

 

Volatile liquid compounds_________________________________________

4. It is likely that methods of extinction will be discussed a bit later.

Methods of extinction____________________________________________

 

5. It is considered that the theory of combustion interference is the same for dry powders and halogenated agents.

 

The theory of combustion interference_______________________________

 

6. It is known that some fires are extinguished by introducing inert gases. Some fires_____________________________________________________

 

7. It is expected that the introduction of halogenated agents, wet and dry chemicals will widen the scope of attack and give firefighter a selectivity of extinguishing media.

 

The introduction of halogenated agents, wet and dry chemicals___________

_____________________________________________________________

 

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8. It is believed that halon destroys the ozone layer.

Halon_________________________________________________________

9. It is alleged that the fire was arson.

The fire_______________________________________________________

 

10. It is thought that defective electrical equipment caused the fire. Defective electrical equipment_____________________________________

 

 

SPEECH PRACTICE EXERCISES 13. Answer the following questions.

 

1. Why is water used for the majority of fires?

2. How can water be applied to the heart of the fire?

3. What is the difference between chemical and mechanical foams?

4. How is foam expansion usually rated?

5. How does foam extinguish the fire?

6. How long have halogenated agents been used for firefighting?

7. What is released from halogenated as they decompose in the fire?

 

8. What is the primary advantage of halogenated agents?

9. What halogenated agents used for firefighting do you know?

10. In what environments are halogenated extinguishing agents often used?

 

11. What may another agents cause if they are discharged in such environments?

 

12. What is a wet chemical agent?

 

13. What class of fires were wet chemical agents specially designed for?

 

14. What are the two methods through which wet chemical extinguishers work on class K fires?

 

15. What is called saponification?

 

16. If you compare the efficiency of plain water and wet chemical agent for the extinction of class A fires, what will be more efficient?

 

17. On what type of fires are dry chemical agents especially efficient?

 

18. What is the relation between particle size of dry chemical and its effectiveness as a fire extinguishing agent?

 

19. What are the mechanisms through which dry chemical agents extinguish fires? What is the main mechanism?

 

20. What acts as a barrier between the fuel and the heat?