The given words in the question are "あるいて" (walking), "ともだち" (friend), "しんかんせん" (bullet train), and "行きます" (go). Among these words, "行きます" (go) is the correct answer as it matches the context of the other words. The phrase "あるいてともだちしんかんせん" can be interpreted as "going by walking with a friend and a bullet train," which implies the action of going somewhere. Therefore, "行きます" (go) is the appropriate word in this context.