1. Represents the English letter

The meaning of the symbol O is a separate English letter O in the English alphabet, ranking 15th, and can be combined with other letters to form words. For example, when open is the English letter, the pronunciation of o is /?u/?.

2. Indicate blood type

O can be used to indicate a person’s blood type, which is type O blood. People with type O blood are one of the groups classified according to blood types A, B, O, and AB. The plasma of type O blood contains anti-A and anti-B. If the red blood cell preparation containing type O plasma is transfused into A, B, and AB Type 1 patients will have varying degrees of immune hemolytic transfusion adverse reactions.

3. Representing chemical elements

O can also be used as a chemical element symbol to represent the oxygen element, which is located in Group VIA of the second period of the periodic table of elements. Oxygen is the most abundant and widely distributed element in the earth's crust. It is also the most important element in the biotic and abiotic worlds. Its content in the earth's crust is 48.6%. Elemental oxygen accounts for 20.9% of the atmosphere.

4. Latin letters

O is the Latin letter. In the Latin alphabet, the position of O is the 15th. It has similar functions to the English letters. Combine to form different meanings and used for communication.

5. Phonetic symbols

O is also a symbol for phonetic symbols. In English phonetic symbols, /o/ is a middle closed back rounded sound, which is an international phonetic symbol. Through learning phonetic symbols, you can It makes people's pronunciation more pure and makes learning English easier.

Baidu Encyclopedia-o (letter symbol)