Que te sugiere esta apreciación

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.

ask your friends for what they got then copy it down if you don't have any friends which is fine than google it or pay the teacher

its probably to later but whats the question