I think I broke the teacher today.
WOW :?? to
XHH: They studied various tests in psychology, and tested on themselves for example. And there was, among other things, the task of illustrating the picture - a wave in a square. Well, give up, the predecessor checks, comments. And then he hangs, intentionally, looks at the sheet, thinks, looks again, eventually asks the drawer to explain what it is, and then said that this is not suitable for any classification.
Guess whose letter it was?
Wow, I guess, so what did you picture there?
Well, I look at a wave of some sort, and I did the first thing that came to mind - the oscillograph.