As the stir cracks and crazes their enamel.
             Soon the sun's warmth makes them shed crystal shells
             Shattering and avalaching on the snow crust--
             Frost's alliteration--here the repetition ofz/ ands/ andk/ sounds--lets us hear as well as see the
             birch trees after a freezing rain and the morning after as the melting begins. Thek/ sound in "crack"
             and "crazes" mimics the sound of the ice in the breeze "shattering" and crashing "on the snow
             crust." It also imitates the crunch of snow under the weight of boots. Thes/ andz/ sounds suggest
             the rising breeze--his use ofs/ sounds increases as it rises. These sounds also suggest the scratch
             and swish of birch branches scraped on
             ...