며칠전에 책을 샀는데요 집에서 읽느라 머리맡이나  책상 위에 올려놓은 적은 있었지만 막 굴러다니지는 않았거든요??  근데 읽다보니 책에 이런게 끼어있네요
이게 뭐죠?? 스티커같이 어딘가에 붙일수있게되어있는것 같은데..