read in turn, circulate a book (among friends)
のです, のだ, んです, んだ
Expression, の and ん add emphasis
the expectation is that ..., the reason is that ..., the fact is that ..., the explanation is that ..., it is that ...
Expression, Godan verb, Usually in kana, usu. sentence ending
1. to have been decided (so) that, to have been arranged (so) that
2. to be the result (of), to be the outcome
3. to be the reason (for)