Advanced Very explanation.

A boy aged four years was eating an apple in the backseat of a car on the way home from school.

He asked his father, who was driving, "Daddy, why is the color of my apple turn brown?"

"Because," replied the father explained, "After you eat the skin, the flesh of apples that will be directly in contact with air, which causes the pulp oxidized with molecules that can alter the structure of the apple fruit, apple fruit so that eventually it changes color. "

After his father finished explaining, the atmosphere was quiet for a while, until suddenly the boy asked softly, "Well, Dad was talking to me huh?"

???!!!!???