I'm reading this book in korean, but I'm a beginner so I my grammar is not that good. I ran into a verb that has the ending ㄴ데서도 (가운데서도). I know what the endings ㄴ데, 어서, and 어도 mean separately, but I have no idea what ㄴ데서도 means. also, what does it mean when there is verb with the 어도 ending twice in a row (i.e. 들어도 들어도)? thanks in advance!!