Knowledge of ancient and modern science and history

1, no matter what kind of calendar, it is nothing more than the arrangement of year, month and day. These arrangements are mainly based on the motion of celestial bodies.

A day is the most recognizable unit of time. One revolution of the earth is a day, and both years and months are based on one day.

2. Western Han Dynasty

3, copper, lead, tin, another way of saying, is copper, tin, zinc.

4. compass. Warring States period.

5,' Nine Chapters Arithmetic'

6. Lin Zexu, born in Houren, Fujian.

7. Jing-Zhang Railway, Zhan Tianyou, Yale University.

8. Feng Ru.

9. Shi Jing Wentong Museum.

10, Yan Fu.

1 1, Liang Qichao.

12, Lin Shu

Darwin, China 13.

14, Tao Xingzhi.

15, Dr. Sun Yat-sen, Li Dazhao.

PS, can you add some points? It's tiring to answer this question. Well, you've been adding,,,