Plants contain the carbohydrates starch and cellulose. In the spring when stem growth is at its fastest rate, cellulose production rates are increased in some plants. In the months with less sunlight, the level of starch decreases in some plants. What does this information
demonstrate?

i think that it is plants

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.