... the similarity of all the questions despite the search and replace attempts to trivially change the variable names in order to generate the appearance of a new question; that it is pretty clear this represents a single person.
Or perhaps it represents attempts on the part of several students to frustrate the efforts of Teacher to simply Google the original variable names and initial data and thereby track down cheaters.
I would also expect much more dissimilarity in the English usage if this were more than one poster.
This could also have an alternate explanation. The poster or posters are obviously using English as a second language. Multiple students, if such they be, may simply have learned the language from a common source and so have a common voice. Inexperience with English may further mask individual differences. I suppose a thoroughgoing textual analysis of all the posts in question might discriminate between one or many voices, but I don't have the fortitude to hurl myself down that particular rabbit hole.
Alas, while all these alternatives are suggestive, I find none, even my own suggestions, conclusive. We are in the fortunate position of being able to continue to speculate endlessly...
Give a man a fish: <%-{-{-{-<
