¿Cuál de las siguientes palabras con el prefijo post- es un sustantivo que significa "un mensaje agregado al final de una letra después de la firma del escritor"? A.

gastos de envío

SEGUNDO.

posmoderno

C.

posdata

RE.

¿posfechar?

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

airlines i think? or a cruise boat? does this work out for u? ?