Como cambiamos los adjetivos del singular al plural?

1) Las palabras que terminan en vocal -A, -E, -O; se les debe agregar "-S".

Ejemplos:

when the outside temperature is too cold, an endothermic animal can generate heat by shivering. endothermic animals must eat much more often than ectothermic animals since it takes energy to maintain a constant body temperature.

guatemala is the correct answer