What is the white line in the sky?

It is a copy that expresses freedom and unknowns. The copy of "a white line in the sky" often appears in the related fields of tourism, outdoor sports or photography. It refers to a white line observed in the sky, which appears in the dark blue area of the sky. Usually, a cloud can be seen or seen at sunrise and sunset. This white line gives people a mysterious and spectacular feeling and is easy to attract people's attention and interest. At the same time, this copy can also be used to express the yearning and exploration spirit for freedom, the unknown and the future, which means pursuing dreams, taking risks and challenging yourself.