How do you tell your'e teacher/principal sorry for being rude through an e-mail. and for telling them "screw this class? " then walking out of their class?

the volume increases

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?