A) to complete - complete - completely - uncompleted - completeness;

B) to protect - protected - unprotected - by protecting - protection - protective;

C) similar - dissimilar - similarly - similarity;

D) worsen - worsening - worse; c) principal - principally;

To contaminate - contaminated - contaminating - contamination - contaminant;

To add - addition - additional - additionally;

Reversible - irreversible - reversibility - nonreversibility;

To erode - eroded - erodibility - erodible - erosion.

Exercise 6. Give Ukrainian equivalents to the following pairs of words with the prefix semi-, meaning "напів-, пів- ".

Model: semi-arid — напівсухий, напівпосуіиливий. Semi-desert (desert - пустеля), semi-humid (humid - вологий), semi-annual (annual - річний), semi-opaque (opaque - прозорий), semi­automatic (automatic - автоматичний), semi-fabricate (fabricate - підробляти).

Exercise 7. Give Ukrainian equivalents to the following pairs of words with the negative prefixes un-, in-, im-:

A) changeable - unchangeable; polluted - unpolluted; protected - unprotected; improved - unimproved; healthy -unhealthy; favourable - unfavourable; contaminated - uncontaminated; explored - unexplored;

B) admissible - inadmissible; fertile - infertile;

C) possible - impossible.

Exercise 8. Match English equivalents to the following words paying attention to the suffixes' meanings.