I bought this last summer and only used it a few times. I was using it without the cover, so there are stains on the front cover inside and some dirt on the back. The cover itself has no stains, so I've marked it as having no noticeable stains. The detachable answer sheets are at the end, but they haven't been completely detached. Inside, there are markings only on the part shown in the fourth photo. *Please refrain from purchasing if you are sensitive to used items.