[지식] 튼살 생기는 이유

LINK : //search.naver.com/search.naver?sm=top_txt&where=nexearch&ie=utf8&query=%ED%8A%BC%EC%82%B4%20%EC%83%9D%EA%B8%B0%EB%8A%94%20%EC%9D%B4%EC%9C%A0