Resources cannot be replaced within a reasonable time but can be replenished in a short period of time and are not diminished over time and are always available in the same amount. a. perpetual, renewable, nonrenewable b. nonrenewable, perpetual, renewable c. nonrenewable, perpetual, renewable d. nonrenewable, renewable, perpetual

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.