Section 5 belongs to euphemism.
1 section always writes about the stagnant water in this ditch. The wind can't move, rot and dull, and it has no vitality and vitality. This is its characteristic. The coolness makes it rot completely and makes the ugliness more obvious.
The second section, directly following the third and fourth sentences of 1, mainly describes the filth and filth of stagnant water statically from the aspect of color.
These four sentences are similar to irony, regarding "Emerald", "Peach Blossom", "Rocky" and "Xia Yun" as the beauty of stagnant water written on the front.
The third section describes the decay and deterioration of stagnant water dynamically. The moldy stagnant water is "full of pearl-like foam", and those rancid products-"water drops" are like a duck to water, giving out complacent "laughter", similar to those "flower mosquitoes" who take the opportunity to make trouble and enjoy this "green wine in the ditch".
The fourth quarter, the stillness of stagnant water, to move against static. With the song of "Frog", the poet effectively highlights the silence of stagnant water, as if listening to birds in an empty mountain.
In the fifth section, in short, the poet created a series of ugly images around stagnant water, hiding hateful feelings behind irony.