There are strict rules on the level of couplets, which are formed according to the level of pronunciation. Generally speaking, the flat voice is the last word of the upper and lower parts, and the last word of the upper and lower parts should be balanced. Therefore, "the historical monument of towering green hills" is the last sentence of the first couplet, and "the national integrity of the red sun" is the last sentence of the second couplet. Due to the coordination of linking, the last sentence of the upper part must be linking and the last sentence of the lower part must be flat.