Е-6

(И) ЕЖУ ПОНЯТНО highly coll these forms only subj-compl with быть» ( subj: это or a clause), pres only fixed WO

the essence of some statement (action, fact etc) is so obvious, so clear that it is impossible not to understand it: это - = anyone (any fool, any half-wit etc) could tell (see) (that)

ift (as) plain as day.

Нина говорит, что не красит волосы, но и ежу понятно, что это неправда. Nina says she doesn't dye her hair, but any fool can see it's not true.