What does Lexicology, a brunch of linguistics study?

What three aspects of composition are there in the English language?

1. 
   They are grammar, neutral and syntactic.
   
2. 
   They are syntactic, morphological and linguistic.
   
3. 
   They are simple, neutral and morphological.
   
4. 
   They are compound, simple and neutral.
   
5. 
   They are neutral, morphological and syntactic.
   

17. 
    What are the four types which represent the main structural types of Modern English words?
    

1. 
   root words, derivatives, compounds and international words.
   
2. 
   root words, derived words, loan words and shortenings.
   
3. 
   root words, derived words, compounds and shortenings.
   
4. 
   compounds, shortenings, homonyms and root words.
   
5. 
   shortenings, loan words, synonyms and root words.
   

17. 
    What is the common word for such terms as "set expressions, fixed word- groups, set phrases"?
    

1. 
   Collocation.
   
2. 
   Unit.
   
3. 
   Phraseological unit.
   
4. 
   Set word-group.
   
5. 
   Phrase group.
   

17. 
    W hat is the basis of the traditional and oldest principle for classifying phraseological unit?
    

1. 
   It is based on tiieir associations.
   
2. 
   It is based on their linguistic characteristics.
   
3. 
   It is based on the semantic principle.
   
4. 
   It is based on their structural characteristics.
   
5. 
   It is based on their original content.
   

17.