Which describes a tropical climate

Tropical climates are characterized by monthly average temperatures of 18 ℃ (64.4 ℉) or higher year-round and feature hot temperatures. ... There are normally only two seasons in tropical climates, a wet season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense.

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.