What is the background of a half-white and half-green chat?

One,

Second,

Picture dictionary explanation:

Figure: The basic terms in technical drawing refer to a form (note that it is a form) in which points, lines, symbols, characters and numbers are used to describe the geometric features, shapes, positions and sizes of things.

Film: nouns, such as records, pictures, photos, movies, flaky stones (flaky stones), wood chips, magnolia slices, shrimp slices, business cards, tiles ... (short description is tangible things).