四、還原信息
Zu Chongzhi is one of the greatest mathematicians in ancient China. He was born during Northern and Southern Dynasties. His family were very talented. They had been studying maths and astronomy（天文學）for generations（世代）. From a young age, Zu was taught natural science, astronomy, maths and so on. 1.
E
Zu was best known for his calculation（計算）of pi. According to historical records, he did all the work using nothing but wooden sticks. 2.
G
No one at that time was able to calculate it more accurately（精確地）than Zu. The achievement（成就）has been accepted around the world. In order to remember Zu, some mathematicians have suggested calling pi “zulüe”（祖率）.
Zu was also famous for working out how to calculate the volume（體積）of a ball. 3.
C
The two recorded their achievement in Zhui Shu. The book was used as a maths textbook during the Tang Dynasty.
4.
D
He worked out that a year should be 365.24281481 days long and created the Daming Calendar. But unluckily, the great mathematician never saw his calendar put into use. 5. ______
F
Almost ten years later, the Daming Calendar was finally accepted.
A. Zu was also an inventor.
B. However, nobody paid attention to the result.
C. He did this with the help of his son Zu Geng.
D. Zu was successful not only in maths but in astronomy.
E. The little boy was interested in all of these subjects, especially（尤其）in maths.
F. After he died, Zu Geng kept on proving（證明）that the new calendar was more accurate.
G. It took him lots of time to work out the value—between 3.1415926 and 3.1415927.
