英文回答：
Percentage signs (%) are mathematical symbols that represent a fraction or proportion of a whole. They are typically used to express quantities as a fraction of 100. For example, 50% represents 50 parts out of 100, which is half of the whole.
Percentage signs can also be used to indicate the change in a value over time. For example, a 10% increase in sales means that sales have increased by 10% of their original value.
In addition to their mathematical uses, percentage signs are also commo ...