Consider a database containing two relations: r(a, b, c) and s(d, e, f). for each of the 12 rewriting rules for relational algebra expression, give an example pair of relational algebra expressions involving r and s for the rule, and give an example pair to show the rewriting rule cannot be used if someof the conditions for the rule is not satisfied. you may want to provide these examples as two tables

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.

To move a file or folder in microsoft windows, you can click and hold down the left mouse button while moving your mouse pointer to the location you want the file or folder to be, which is also known as.

Why might you choose to create a functional resume