Have (one's) nose in a book informal
Said when someone reads books all the time
Whenever I come to visit Jenny's house, I notice that she always has her nose in a book.
He is a really bookworm. He always has his nose in a book.
read a book comfortably
The verb "have" should be conjugated according to its tense.
To decide to believe someone‘s saying although they may not tell the truth
He said that he was late because he had an accident and I gave him the benefit of the doubt.