М. М. Кутепова The World of Chemistry Мир

In ancient times gold ... the most perfect metal.

1. 
   considered c) has considered
   
2. 
   was considered d) has been considered
   

5. 
   Boyle ... in experimental method.
   

1. 
   believed c) will believe
   
2. 
   has believed d) was believed
   

5. 
   Outstanding achievements... in the structure of atom.
   

1. 
   make c) have been made
   
2. 
   made d) is made
   

5. 
   You’ve got a bachelor’s degree in chemistry,... ?
   

1. 
   didn’t you? c) don’t you?
   
2. 
   haven’t you? d) aren’t you?
   

Section 3
Put C if the sentence is correct. Put X if there is a mistake in the use of the modal verbs.

5. 
   It was decided that metals and nonmetals can be given different names.
   
6. 
   Matter can occupy three different states.
   
7. 
   Could you show me his calculations?
   
8. 
   Water must exist as a liquid, as a gas, or as a solid.
   
9. 
   Water can be decomposed.
   
10. 
    This experiment is to give good results.
    
11. 
    Water for washing must contain substances that react with soap.
    
12. 
    If we condense the steam, we are thus able to remove all the impurities except volatile ones.
    

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5. 
   At one time the ancients thought that everything should be made up of earth, air and water.
   
6. 
   No chemist has been able to separate any other substances from mercury, oxygen or hydrogen.
   
7. 
   Atoms of elements may be arranged in different ways to form molecules of different types of matter.
   
8.