Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 29 to 33.

How men first learnt to (29) ____words is unknown; in other words, the origin of language is a mystery. All we really know is that men, unlike animals, somehow invented certain sounds to express thought and feelings, actions and things, so that they could communicate (30)____ each other; and that later they agreed upon certain signs, called letters, which could be combined to present those sounds, and which could be written down. Those sounds, whether spoken or written in letters, we call words. The power of words, then, lies in their associations - the things they bring up  before our minds. Words become filled with meaning for us by experience; and the longer we live, the more certain words recall to us the glad and sad events of our past; and the more we read and learn, the more the number of words that mean something (31) ____. Great writers are those (32)_____ not only have great thoughts but also express these thoughts in words which appeal powerfully to our minds and emotions. This charming and telling use of words is what we call literary style. Above all, the real poet is a master of words. He can convey his meaning in words which sing like music and which by their position and association can move men to tears. We should therefore learn to choose our words carefully and use them (33)____ ,or they will make our speech silly and vulgar. What is true about words?

How men first learnt to (29) ____words is unknown; in other words, the origin of language is a mystery.