I really need the answer ASAP .
Explain how combustion affects the carbon cycle?

Explanation:

combustion happens when we dig up fossil fuel and burn it, so when we do that whatever is left goes into the air starting the carbon cycle again

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.

what is this saying?