Wave in which particles in the medium vibrate back and forth along the path the wave travels

Tanya was used to using word, and she did some work for her brother mike, who was using wordperfect. tanya was quickly able to use wordperfect for windows with little difficulty, since many of the commands for it were the same as the commands for word. tanya's ability to use wordperfect best illustrates:

What was one step that charlemagne took to unite his kingdom? a. he chose a single strong heir to inherit his throne. b. he drove muslim forces out of europe. c. he created and supported schools. d. he declared himself head of the catholic church.

How does sociology account for the cause of drug and alcohol addiction?