The ancestral mollusk was a small creature with a tiny shell, How did the struggle for survival create so many different types of modern molluscs?

idk what the options are but

these is a strong electrostatic attraction between the ions hence a lot of energy is needed to overcome this attraction

this is why the boiling points are so high

la transducción de señal ocurre cuando una molécula de señalización de fluido extracelular activa un receptor de superficie de la célula.

answerwestern plateau,     central lowlands,     great dividing range;