Well you do not have a set of choices but here is an example!
Sweating, your body releases water to cool down the skin of your body!
An atom is unlikely to react when it is stable. That is when it's shell is complete. Due to the completion of the shell, no other electron can combine through any form of bonding. Hope i helped.
Answer:
Vertebrates are further classified according to several criteria like exoskeleton, respiratory organs, method of giving birth, number of chambers in heart, mode of living etc. They are further classified into classes Pisces, Amphibia, Reptilia, Aves and Mammals