Why did Shang people carve characters on turtle shells?

In Shang Dynasty in China, a popular writing was Oracle Bone Inscriptions. In fact, Oracle Bone Inscriptions was already used in the late Shang Dynasty and the Western Zhou Dynasty in China. Carved on the shoulder blades of tortoiseshell or cattle, many of them are grotesque. So far, people haven't I don't know what they mean. So what is the reason for engraving on tortoise shells or cattle shoulder blades?

In fact, we can know from the left literature that tortoise shells were used for divination in the Zhou and Shang Dynasties at that time. Due to the feudal mentality at that time, people carved characters on tortoise shells, which could predict whether something was fierce or auspicious. There is a saying in Zuo Zhuan: The tortoise elephant is also a good omen.

The so-called divination is divination according to the change of numbers. According to the literature, people began to have this kind of behavior in Shang Dynasty. Besides, before Zhou Wuwang moved to the capital, the use of tortoise shells was considered as outdated luck. So at that time, not only the people believed in divination, but also the emperor believed in tortoise shell divination.

In the process of modern archaeology, our archaeologists have discovered many divinations with tortoise shells and cattle shoulder blades, leaving us with many Oracle Bone Inscriptions and unearthed many. Fragments of Oracle Bone Inscriptions were unearthed in Shanxi, Shaanxi, Beiping and other places in China, which also led many historians in China to have a strong interest in Oracle Bone Inscriptions. According to the unearthed conditions, we can find that Oracle Bone Inscriptions has certain similarities. This shows that the role of Oracle bones and cattle scapula is always the same, and the method of divination is also inherited and will not change at any time. But there are still many Oracle Bone Inscriptions, and we don't-I don't understand what this means. I hope I can understand later.