Which of the following is NOT part of natural selection? a) Individuals best suited to a particular environment will reproduce more
b) Individuals best suited to a particular environment will survive more
c) There is a struggle for survival
d) Evolution causes more complex & perfect organisms

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.