Explain the 4 major technological actions?

PLEASE HURRY!

Write lines of verse that rhyme to remember the following information: acid rain is a type of air pollution caused by chemicals in the air.

Me with this program in c++ ! computers represent color by combining sub-colors red, green, and blue (rgb). each sub-color's value can range from 0 to 255. thus (255, 0, 0) is bright red. (130, 0, 130) is a medium purple. (0, 0, 0) is black, (255, 255, 255) is white, and (40, 40, 40) is a dark gray. (130, 50, 130) is a faded purple, due to the (50, 50, 50) gray part. (in other word, equal amounts of red, green, blue yield gray).given values for red, green, and blue, remove the gray part. ex: if the input is 130 50 130, the output is: 80 0 80. thus, find the smallest value, and then subtract it from all three values, thus removing the gray.

What is the primary difference between the header section of a document and the body? a. the body is displayed on the webpage and the header is not. b. the header is displayed on the webpage and the body is not. c. the tag for the body is self-closing, but the tags for the headers must be closed. d. the tag for the header is self closing, but the tag for the body must be closed.