If you need to upload or email your teacher a homework. You can usually create a ZIP file with documents that look legit.
Then open it with a code editor (like sublime-text) and remove random chunks of the code you see, until the file can't be unzipped anymore.
Your teacher will email you back saying they can't open the file you sent in a few days, just apologize and send the correct one.
In one instance the teacher didn't bother to email me back and I got a passing grade without even hearing about it.
(this also works with Word documents, PDFs etc ..)
Don't use this more then once per teacher, I've learned my lesson already 😂.