夹克?

A夹克 is a piece of clothing that is worn on the upper body, typically for warmth or protection. It can be made of a variety of materials, including wool, cotton, and synthetic fibers. A jacket can be worn over other clothing, such as a shirt or sweater, or it can be worn on its own.

What is the function of a jacket?

A jacket's main function is to provide warmth and protection from the elements. It can also be used to regulate body temperature, and to provide a sense of style and comfort.