Talk about the main content of the text.

Section 1: The bridge opening of the stone arch bridge is curved;

Section 2: Stone arch bridge has a long history, beautiful shape and solid structure;

The third paragraph: the stone arch bridge in China has a long history, is widely distributed, has various forms, and has many amazing masterpieces;

The fourth paragraph: Zhao Zhouqiao has a long history and a solid structure;

The fifth paragraph: Zhao Zhouqiao has scientific design and ingenious technology;

The sixth paragraph: Lugou Bridge has firm structure, ingenious technology and scientific design;

Paragraph 7: Lugou Bridge is world-famous and beautifully built;

Paragraph 8: Lugou Bridge is of great commemorative significance in the history of our country;

The ninth paragraph: the reasons for the brilliant achievements of China's stone arch bridge;

The tenth paragraph: China's bridge industry is developed.

Extended data:

This paper explains the length and width with specific figures, quotes Zhang's exquisite praise of design and construction in Tang Dynasty, and expounds the originality and artistic value in design and construction from four aspects. The first point is that the arch has a small radian, which is convenient for cars and horses to get up and down.

The second and third points are explained from the originality of bridge arch design, that is, "the big arch has two small arches on each shoulder" and "the big arch consists of 28 arch rings", which makes the bridge durable. The fourth point is that the bridge is in harmony with the surrounding scenery.

The article introduces Lugou Bridge in the same order. After introducing the characteristics of Chinese stone arch bridge, the author explains the reasons why Chinese stone arch bridge has made such brilliant achievements from three aspects. This article is full of deep admiration for the diligence and wisdom of the ancient working people.