Make a short summary of the text.

 

Find the synonyms of the following words in the text.

1. to change - … 5. permanent - …

2. to form a sediment - … 6. blocking - …

3. to immerse - … 7. exact - …

4. coefficient - … 8. to set down - …

Find the opposites of the following words in the text.

1. upstream - … 5. vertical - …

2. natural - … 6. accurate - …

3. restricted - … 7. worst - …

4. variable - … 8. sharp - …

Fill in the correct prepositions where necessary.

1) to result ___ smth.; 2) to be ___ right angle; 3)___ addition; 4) to measure ___ sth. ___ smth; 5) to be made ___ iron; 6) to be installed ___ the straight section; 7) to provide ___ an error ___ measurements.