Sasha had a test coming up in a very difficult subject, so Sasha spent the whole day studying.
I spent all day studying because I have an exam in Chemistry.  It'll be a very difficult test. At least you are studying for it. I am too scared not to study.  I don't want to fail the test. what is your grade in Chemistry? It could be a C or C- judging from my midterm. Alright, I guess you better study some more.