Electromechanical products. China has always been a big manufacturing country, and the export of mechanical and electrical products is essential. Mechanical and electrical products are the most exported products in China, with an annual export value of about $654.38+02 billion. China, with Chinese civilization as its source and Chinese culture as its foundation, is one of the countries with the longest history in the world. People of all ethnic groups in China have jointly created a splendid culture with a glorious revolutionary tradition. China is a multi-ethnic country with the Han nationality as the main body. Commonly used Chinese and Chinese characters. The Han nationality and ethnic minorities are collectively called "Chinese nation", and they also call themselves "descendants of the Yellow Emperor" and "descendants of dragons". China is one of the four ancient civilizations in the world. About 5800 years ago, there were signs of the origin of civilization in the Yellow River, the middle and lower reaches of the Yangtze River and the West Liaohe River. Around 5300, various regions of China entered the stage of civilization one after another; About 3800 years ago.