A、By their function. B、By their properties. C、By increase of our experience. D、By association with other things. C[听力原文] How do

How men first learnt to invent words is unknown. All we really know is that men, unlike animals, somehow use certain sounds to express thoughts and feelings, actions and things, So that they could communicate with each other; and that later they agreed upon certain signs, called letters, which could be combined to represent th6se 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 with the things they bring up before our minds. Words become filled with meaning for us by experience; and the more certain words recall to us the more glad or sad events of our past arc; and the more we read and learn, the more the number of words that means something to us increases.
   Great writers are those who 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 accurately.