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.
Many persons of good education unconsciously circumscribe themselves ___________ a small vocabulary. They have a knowledge of hundreds of desirable wordswhich they do not put _________ practical use in their speech or writing. Many, too, are conscious __________ a poverty of language, which engenders in them a senseof timidity and self-___________. The method used for building a large vocabulary has __________ been confined to the study of single words.