1. Four Great Inventions:
(1) Papermaking: In the first year of the Eastern Han Dynasty and Emperor Yuanxing (AD 15), Cai Lun made plant fiber paper suitable for writing with bark, broken fishing nets, rags and hemp heads as raw materials, and improved the papermaking technology, which made the paper widely used by people. Known as Cai Hou paper. "
(2) Compass: a simple instrument used to determine the direction. Formerly known as Sina. The main component is a magnetic needle (commonly known as a magnet) which can rotate freely on a shaft. The magnetic needle can be kept in the tangential direction of magnetic meridian under the action of geomagnetic field. The north pole of the magnetic needle points to the geographical south pole, and this property can be used to distinguish the direction. Commonly used in navigation, geodesy, travel and military affairs
(3) Gunpowder: It is made by mixing saltpeter, sulfur and charcoal. At that time, people used these three things as medicines to treat diseases, so it was named Gunpowder, which means medicine on fire.
(4) Movable type printing: It started with block printing in the Sui Dynasty, developed and perfected by Bi Sheng in Song Renzong, and produced movable type printing, which was spread to Europe by Mongols, so later people called Bi Sheng the ancestor of printing.
2. Terracotta Warriors and Horses of Qin Shihuang
Terracotta Warriors and Horses of Qin Shihuang are a category of ancient tomb sculptures. In ancient times, human sacrifice was practiced, and slaves were accessories of slave owners before their death. After their death, slaves had to be buried with slave owners, which was a sacrificial object. The Terracotta Warriors and Horses are made into sacrificial objects in the shape of military forces (chariots, horses and soldiers)
3. The Forbidden City
The Forbidden City is located in the center of Beijing, and was formerly called the Forbidden City. It is the imperial palace of Ming and Qing dynasties, an unparalleled masterpiece of ancient architecture, and the largest and most complete ancient wooden structure complex in the world.
4. Dunhuang murals
Dunhuang is a county-level city under the jurisdiction of Jiuquan City, Gansu Province, and a national historical and cultural city in China. Dunhuang, located on the Silk Road, the main road leading to the western regions, Central Asia and Europe in ancient China, once had prosperous business activities. Known for its Dunhuang Grottoes and Dunhuang Murals, it is the site of the Mogao Grottoes, a world heritage site, and Yumenguan and Yangguan on the border of the Great Wall of Han Dynasty.
5. Dujiangyan Water Conservancy Project
In 256 BC, during the Warring States Period, the Dujiangyan Water Conservancy Project led by Li Bing, the prefect of Shu County of Qin State, was located on the Minjiang River on the west side of Dujiangyan City in the west of Chengdu Plain, Sichuan Province, 56 kilometers away from Chengdu. The large-scale water conservancy project is still irrigating farmland, which is a great water conservancy project for the benefit of the people. It is characterized by long time and no dam to divert water, and it is the originator of world water conservancy culture. This project is mainly composed of three parts, namely, fishmouth water diversion dike, spillway of Feisha weir, water inlet of Baokou, Baizhang dike, herringbone dike and other ancillary works. It scientifically solves the problems of automatic river diversion (fishmouth water diversion dike divides water into four or six parts), automatic sand discharge (fishmouth water diversion dike divides sand into two or eight parts), and controls the water inflow (Baokou and Feisha weir), thus eliminating the flood.