Exercise 4. Make sentences

1) A piece of paper…. 2) Freshly cut wood…   3) This process… 4) Carbon… 5) Methanol… 6) Volatile compounds... 7) Coal tar, coal gas, alcohols, formaldehyde and ammonia... 8) Hydrocarbons...

…drives off…   …combines with…   …evaporate from… …turn into… …contains… …can be distilled out of… …bursts into…     …is referred to as…

…carbon dioxide and water when they burn. …oxygen to produce carbon dioxide. ... flame. …“wood alcohol”. …the wood when heated. …a lot of water. …the smoke.   …all the volatile organic compounds.

Exercise 5. Multiple-choice questions. Choose the right answer.

1) Ash is the non-burnable mineral in the tree’s cells, like... (calcium, potassium, magnesium; iron, carbon, copper).

2) Freshly cut wood contains a lot of... (sap; water; oil).

3) (Cellulose; tar; clay)... is a chief component of wood.

4) When you light charcoal, what is burning is pure... (water; carbon; carbon dioxide).

5) Coke is coal that has been heated in the absence of oxygen to drive off... (heat; the organics; cells).

Exercise 6. Ask questions on the text.

1) The new fuel produces a lot of smoke as it heats up. (What? When?)

2) The smoke that this process produces is actually very valuable. (What...like? Why?)

3) A charcoal fire is a fire that has burned down to embers. (What?)

4) When the tree was alive it contained a wide variety of volatile hydrocarbon in its cells. (When? What?)

5) Carbon combines with oxygen to produce carbon dioxide. (What... with? What?)

Exercise 7. Answer the questions

1) What things can one find in any piece of wood?

2) What contains more water, freshly cut wood or seasoned wood?

3) What is the chief component of wood?

4) What is ash?

5) Why does smoke come from a fire?

6) Can you see smoke from a charcoal? Why?

7) What is coke?

8) What valuable substances does coke smoke contain?