1. During the "Secret War" (1959- 1975) or "Laos Civil War", the United States flew more than 500,000 missions to this small Southeast Asian country, dropping more bombs than Germany and Japan combined during World War II.

2. During the Second World War, every soldier on the battlefield had 17 people to support the soldiers in the rear (doing logistics, supply chain, intelligence, transportation, etc.). ).

In the late Middle Ages, books were so precious that libraries even locked them on the shelves.

4. Harvard University, a famous American university, was founded in the ninth year of Daming Chongzhen and the first year of Qing Chongde (the first year of Huang Taiji). Oxford University was founded in 1 167, which was the main road in the Southern Song Dynasty for three years.

In the past 3000 years, there was only 240 years of peace in the world.

6. 1945 The atomic bomb dropped on Hiroshima, Japan was mainly supplied by Belgium, which itself did not produce uranium. At that time, Congo in Africa was a colonial country of Belgium, which refined the local uranium and sold it to Americans.

7. The word "oil" sounds very modern, but it was actually named by Shen Kuo, a scientist in the Northern Song Dynasty. In Meng Qian Bi Tan, Shen Kuo recorded in detail the discovery and exploitation of oil a long time ago, and left a prediction that "this thing will be popular all over the world".

8. The Great Wall we see now is relatively new, and all dynasties are constantly strengthening and repairing it. As early as more than 4000 years ago, there were records of city walls as a defense. According to records, it was first built by Qin, Zhao and Yan countries to defend the nomadic people in the north. At that time, the Great Wall was relatively simple.

9. All parts of Australia accept prisoners from Britain and Ireland from 1788 to 1868, Sydney from 1788, Melbourne from 1803, Tasmania from 1820 and Brisbane from1820.

10, the so-called "photos after death" was very popular in Victorian England. In order to preserve the memory of the deceased relatives, the body was chemically treated and posed as a living person to take photos with his family.