(2) The first sentence of these two poems describes the frontier fortress autumn scenery (or the scene of frontier fortress first frost), and the second sentence is isomorphic with the frontier fortress moon, forming an atmosphere of listening to songs (or exaggerating the atmosphere of listening to songs), which lays a sad emotional tone for the whole poem and implicitly expresses the loneliness of recruiting people in frontier fortress. (That's right)
Example 1: They all use the word "frost" to indicate the described season and environment. In autumn, first frost created a sense of sadness, and they also wrote the location and background of writing and the mood of the soldiers guarding the border. Melancholy is expressed implicitly through images, which means endless.
Example 2: They all start with the word "frost". This writing can introduce the season at that time and express the author's inner feelings. Through the scene of "frosty sky", it is more helpful for the author to express his inner feelings and express the theme of the poem.