In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.

The most powerful and the most perfect ____________ of thought and feeling through the medium of oral language must be traced to the mastery of words. ___________ is better suited to lead speakers and readers ___________ English into an easy control of this language than the command of the phrase that perfectly expresses the thought. Every speaker's aim is to be heard and _____________. A clear, crisp _____________ holds an audience as by the spell of some irresistible power.