[plt-scheme] cutting and pasting snips

Can we please have as a default that anything cut out of the 
Interactions window when it is running one of the teaching languages is 
just plain text and not a snip? Despite repeated instructions to the 
contrary, some of my students are creating examples and tests by 
evaluating expressions and then pasting the results into the Definitions 
window. The resulting file is unreadable as a text file, which is how we 
are processing it. We are of course yelling at the students and docking 
them marks, but I'd much rather just not have the problem in the first 
place. Many thanks. --PR