The abundance of water in liquid, solid and gaseous state is a matter of common observation. Water is not only the most abundant compound, but it is also very important for life. To be sure life would be impossible without water.
For many purposes water must be pure. The purest natural water is rain. But we can't say that it is really pure. The same can be said about ground water. It contains a great deal of impurities which fail to settle. Dissolved substances do not settle and don't evaporate with water, and this makes their removal difficult. One of the most important problems is to obtain water sufficiently pure to meet our needs. The choice what process is to be used for purification of water depends upon the uses for which it is intended as well as the impurities it contains. Water used for steam boilers should be free from substances that cause corrosion and scale formation. Water for washing should not contain substances that react with soap. When water is to be used for drinking, it is necessary to kill the microbes it may contain. To achieve this, water which is to be purified is thoroughly filtered.
Another way to purify water is to boil it. None of these methods is fit for producing pure water in the chemical sense, because most of the soluble salts are unaffected by the treatment. To remove these and to prepare chemically pure water suitable for scientific use, we take advantage of the fact that water is usually changed to steam while most of the dissolved substances as have already been mentioned are not volatile. If we condense the steam, we are thus able to remove all the impurities except volatile ones. This process is called distillation. Distilled water has many uses, both in the laboratory and in industry, when even small quantities of impurities are undesirable.
Vocabulary
dissolve
purify
pure
ground
removal
scale
abundance
compound
volatile
a great deal
Answer the questions
1. What is water?
2. What is the purest natural water?
3. What makes the process of purification difficult?
4. What does the choice what process is to be used for purification of water depend upon? Enumerate these processes.
5. How do you understand ''pure water in the chemical sense''?
6. Can you explain what distillation is?
3. Make a report Why is water so important?
Future Continuous Tense
Future Continuous, Future Progressive () . , , , .
| (positive form) | ||
| (person) | (number) | |
| (singular) | (plural) | |
| I will be cook ing | We will be cook ing | |
| You will be cook ing | You will be cook ing | |
| He, She, It will be cook ing | They will be cook ing | |
| (interrogative form) | ||
| (person) | (number) | |
| (singular) | (plural) | |
| Will I be cook ing | Will we be cook ing | |
| Will you be cook ing | Will you be cook ing | |
| Will he, she, it be cook ing | Will they be cook ing | |
| (negative form) | ||
| (person) | (number) | |
| (singular) | (plural) | |
| I will not be cook ing | We will not be cook ing | |
| You will not be cook ing | You will not be cook ing | |
| He, She, It will not be cook ing | They will not be cook ing |
,
|
|
|
Future Continuous Tense
| all day long | |
| this time tomorrow | |
| all day tomorrow | |
| the whole morning/evening/day | // |
| from 6 till 8 p.m. | 6 8 |
Exercises
Ex. 1
Open the brackets using Future Continuous Tense
1. She (to sleep) at home the whole day tomorrow.
2.They (to stay) at a new hotel.
3.I (to live) in Kyiv for the next few weeks.
4. He (to write) a letter at that time.
5. You (to do) your home task all these days?
6. They (to enjoy) the sunshine on the beach?
7. Victor (to read) the whole night?
8. We (to have) coffee?
9. Tony (to have) a bath at this time?
10. Where you (to wait) for me?
11. Susan (to do) at nine oclock tomorrow?
12. When he (to pass) his exam?
13. When she (to type) letters?
14. We (not to speak) at ten oclock.
Ex. 2
