What is the reason that friction is present in surface to surface contact?

there is water in the lubricant

surfaces have microscopic peaks and valleys

one surface is larger than the other surface

surfaces are very smooth and highly polished

Im doing this last minute and literally none of my neighbors or people that my dad works with use excel so if anyone could me make up an example

Why were most movies from the late 1890s until the early 1930s only filmed in black and white? there were only a few people who could afford the technology to produce color motion pictures back then. audiences did not want color motion pictures until later. the film used to make color motion pictures often overheated, which was a safety hazard, so it was generally not allowed. color films had to be hand-colored, frame by frame.

Amitha writes up a one-page summary of a novel during her summer internship at a publishing company. when she reads over the page, she realizes she used the word “foreshadow” seven times, and she would like to reduce the repetition. which tool would best amitha solve this problem?