Пожалуйста помогите составить диалог по английскому с такими идиомами как: bite his head off, off the top of my head, by heart, heart to heart.

A: I cant go to the gym with you because I have to learn a lot of information by heart. 
B: But, why? You usually learn nothing and always get excellent marks!
A: Not this time, Im afraid. We have a new history teacher and he is extremely strict. And If I try to answer anything off the top of my head, he will bite my head off and  Ill face a lot of problems at school. 
В: Oh, I didnt think that he is so severe... But, in my opinion, you should have a heart-to-heart with him and explain to him that youre going to take part in a very important competition and have to train a lot. He is a wise man and he will understand it.