Problems about studio lighting and background cloth ~ ~

The background cloth should be milky white, which is what you see. Definitely not pure white. Lighting should be the effect of a single light. The background of this mopping floor will form different reflections because of different directions, and the background in the foreground will reflect less and appear darker because of tiling; The background in the background is perpendicular to the camera, so the reflection is stronger and brighter. Not a master, just to earn points.