F an organism is successful in a particular environment, Choose... reproduction is Choose... . However, if an environment changes, some offspring of Choose... reproduction may have a better chance of survival and reproductive success than others in a population because of Choose... .

i do not know and i have a 100 in this class

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.

if you listed your answers right then i believe your answer is b.