Why do Li Bai and Du Fu have the highest achievements in poetry?

Du Fu's "Cottage Blown by Autumn Wind": In August, the wind roared and Sanhe grass rolled in my house. Hair flew over the river and sprinkled on the periphery of the river. The highest one hangs a long forest tip, and the lower one floats to Shentang 'ao. The children in Nancun bully me. I can stand being a thief. I openly carried Mao into the bamboo forest, and my lips were so dry that I couldn't breathe. When I came back, I sighed on crutches. In an instant, the wind will set the color of the clouds and ink, and the autumn will be bleak and dark. This cloth has been as cold as iron for many years, and Joule has been lying down and cracking. There is no dry place in the bedside table, and the feet are numb with rain. How can you get wet all night since you are in a mess and don't get enough sleep! There are tens of millions of luxury houses in Ande, which greatly protect the poor in the world, with a spring breeze and a mountain of wind and rain. Oh! When I suddenly see this house in front of me, I will freeze to death alone!

The first three paragraphs laid a solid foundation for the lyricism of the latter paragraph. ? "There are thousands of spacious buildings in Qian Qian, and the poor in the world are happy, and the wind and rain are as calm as a mountain." Seven characters are used before and after, and nine characters are used in the middle. The words "Guangsha", "Thousand Rooms", "Great Shelter", "Tianxia", "Happy Face" and "Anrushan" are loud and clear.

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