Question

what have you done to know the internal and external features of the heart

Answer 1

To know the Internal and External parts of a heat I had done two things:
           1. I hade cut opened and seen the Interior of a goat's heart.I had done this in the presence of adults.
           2. And I had studied the information given in my textbook about the heart and understood it by seeing the goat's heart.

These are the things I had done to know about the Interior and Exterior of a heart.