The phrase <em>with exciting plots </em>is used as D. adjective phrase, because it modifies the noun <em>books.
</em>What kind of books? - (The ones) with exciting plots. <em>
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The answer to the question above is true that the word 'competent' is used correctly in the "it is important to use competent sources when researching" sentence<span>. The word "competent" means a characteristic of acceptable and satisfactory. The sentence above means that it is important to use acceptable sources for a research.</span>
A increase in the trade iconamies happened